32581 + Interview Questions in Mathematics

1.	Match the following to their roots.
Answer» Match the following to their roots.

Discussion

2.	The distance between the points P(3, 2) and Q(–4, 5) is
Answer» The distance between the points P(3, 2) and Q(–4, 5) is

Discussion

3.	In racing over a given dis†an ce d at uniform speed, A can beat B by 30 meters,B can beat C by 20 meters and A can beat C by 48 meters.Find 'd' in meters.
Answer» In racing over a given dis†an ce d at uniform speed, A can beat B by 30 meters,B can beat C by 20 meters and A can beat C by 48 meters.Find 'd' in meters.

Discussion

4.	Which of the following expression gives the value of "s". "s" is given as 12+22+32+42+................+72
Answer» Which of the following expression gives the value of "s". "s" is given as $1^{2} + 2^{2} + 3^{2} + 4^{2} + . . . . . . . . . . . . . . . . + 7^{2}$

Discussion

5.	In the given figure, ABCD is a trapezium with AB \|\| DC, AB = 18 cm DC = 32 cm and the distance between AB and DC is 14 cm. Circles of equal radii 7 cm with centres A, B, C and D have been drawn. Then find the area of the shaded region.(Use π=227 [CBSE 2014]
Answer» In the given figure, ABCD is a trapezium with AB \|\| DC, AB = 18 cm DC = 32 cm and the distance between AB and DC is 14 cm. Circles of equal radii 7 cm with centres A, B, C and D have been drawn. Then find the area of the shaded region. (Use $π = \frac{22}{7}$ [CBSE 2014]

Discussion

6.	A cubical vessel of height 1m is full of water. The minnimum work in taking water out from vessel will be, 1. 5000J 2. 10000 J 3. 5 J 4. 10 J
Answer» A cubical vessel of height 1m is full of water. The minnimum work in taking water out from vessel will be, 1. 5000J 2. 10000 J 3. 5 J 4. 10 J

Discussion

7.	Show that each of the progressions given below is an AP. Find the first term, common difference and next term of each.(i) 9, 15, 21, 27, ...(ii) 11, 6, 1, −4, ...(iii) −1, -56, -23, -12, ...(iv) 2, 8, 18, 32, ...(v) 20, 45, 80, 125, ...
Answer» Show that each of the progressions given below is an AP. Find the first term, common difference and next term of each. (i) 9, 15, 21, 27, ... (ii) 11, 6, 1, −4, ... (iii) −1, $\frac{- 5}{6}$ , $\frac{- 2}{3}$ , $\frac{- 1}{2}$ , ... (iv) $\sqrt{2}, \sqrt{8}, \sqrt{18}, \sqrt{32}, . . .$ (v) $\sqrt{20}, \sqrt{45}, \sqrt{80}, \sqrt{125}, . . .$

Discussion

8.	If the vertices of a triangle are (2,0) (0,2) (4,6), then the equation of the median through the vertex (2,0) is
Answer» If the vertices of a triangle are (2,0) (0,2) (4,6), then the equation of the median through the vertex (2,0) is

Discussion

9.	If cotA+1cotA=2, find the value of cot2A+1cot2A.
Answer» If $cot A + \frac{1}{cot A} = 2,$ find the value of ${cot}^{2} A + \frac{1}{{cot}^{2} A .}$

Discussion

10.	What is the value of sin θ×cosec θ×cot θ= ?
Answer» What is the value of $s i n θ \times c o s e c θ \times c o t θ =$ ?

Discussion

11.	Factorize √3 x2 + 5x + 2√3 = 0 by splitting the middle term and find the value of x.
Answer» Factorize $\sqrt{3}$ $x^{2}$ + 5x + 2 $\sqrt{3}$ = 0 by splitting the middle term and find the value of x.

Discussion

12.	Divya and Dev jointly started a food cart business by investing Rs. 20,000 and Rs. 40,000. After 5 months Divya invested Rs. 10,000 more in the business but Dev withdrew Rs. 20,000. At the end of the year, if the profit of the business is Rs. 1,30,000, what is the profit earned by Divya?
Answer» Divya and Dev jointly started a food cart business by investing Rs. 20,000 and Rs. 40,000. After 5 months Divya invested Rs. 10,000 more in the business but Dev withdrew Rs. 20,000. At the end of the year, if the profit of the business is Rs. 1,30,000, what is the profit earned by Divya?

Discussion

13.	143. Z=(1+i)(1-i)/ (2+i) fibd log z
Answer» 143. Z=(1+i)(1-i)/ (2+i) fibd log z

Discussion

14.	The value of x+y+z is 15 if a,x,y,z,b are in A.P. while the value of 1x+1y+1z is 53 if a,x,y,z,b are in H. P. Then the value of and b are
Answer» The value of $x + y + z i s 15 i f a, x, y, z, b$ are in A.P. while the value of $\frac{1}{x} + \frac{1}{y} + \frac{1}{z} i s \frac{5}{3} i f a, x, y, z, b$ are in H. P. Then the value of and b are

Discussion

15.	A cylindrical vessel with internal diameter 10 cm and height 10.5 cm is full of water. A solid cone of base diameter 7 cm and height 6 cm is completely immersed in water. Find the volume of water (i) displaced out of the cylinder (ii) left in the cylinder.
Answer» A cylindrical vessel with internal diameter 10 cm and height 10.5 cm is full of water. A solid cone of base diameter 7 cm and height 6 cm is completely immersed in water. Find the volume of water (i) displaced out of the cylinder (ii) left in the cylinder.

Discussion

16.	If A={1,2,3,4,5,6}, B={1,2}, then A-(A-B) is equal to
Answer» If A={1,2,3,4,5,6}, B={1,2}, then A-(A-B) is equal to

Discussion

17.	A square of side 5 centimetres and four isosceles triangles, each of one side 5 centimetres and the height to the opposite vertex 8 centimetres; these are to be joined to make a square pyramind. How much paper is needed for the job?
Answer» A square of side 5 centimetres and four isosceles triangles, each of one side 5 centimetres and the height to the opposite vertex 8 centimetres; these are to be joined to make a square pyramind. How much paper is needed for the job?

Discussion

18.	If 512 is as much as 16 times 32, then it can be represented using the equation
Answer» If 512 is as much as 16 times 32, then it can be represented using the equation

Discussion

19.	The height of water level in a circular well is 7 m and its diameter is 10 m. Calculate the volume of water stored in the well.
Answer» The height of water level in a circular well is 7 m and its diameter is 10 m. Calculate the volume of water stored in the well.

19.

The height of water level in a circular well is 7 m and its diameter is 10 m. Calculate the volume of water stored in the well.

Answer»

The height of water level in a circular well is 7 m and its diameter is 10 m. Calculate the volume of water stored in the well.

Discussion

20.	Prove that the points (2, 3), (7, 5), (9, 8), (4, 6) are the vertices of a parallelogram.
Answer» Prove that the points (2, 3), (7, 5), (9, 8), (4, 6) are the vertices of a parallelogram.

Discussion

21.	f(x)=x^2 + x + 1 how to show that it is an one one function or not
Answer» f(x)=x^2 + x + 1 how to show that it is an one one function or not

Discussion

22.	The total surface area of hollow cylinder having the inner and outer radii as R2 and R is xπR(R+L4). Find x.3
Answer» The total surface area of hollow cylinder having the inner and outer radii as $\frac{R}{2}$ and $R$ is $x π R (R + \frac{L}{4})$ . Find x. 3

Discussion

23.	Prove that the lengths of tangents drawn from an external point to a circle are equal. Using the above, prove the following:A quadrilateral ABCD is drawn to circumscribe a circle. Prove that AB + CD = AD + BC
Answer» Prove that the lengths of tangents drawn from an external point to a circle are equal. Using the above, prove the following: A quadrilateral ABCD is drawn to circumscribe a circle. Prove that AB + CD = AD + BC

23.

Prove that the lengths of tangents drawn from an external point to a circle are equal. Using the above, prove the following:A quadrilateral ABCD is drawn to circumscribe a circle. Prove that AB + CD = AD + BC

Answer»

Prove that the lengths of tangents drawn from an external point to a circle are equal. Using the above, prove the following:

A quadrilateral ABCD is drawn to circumscribe a circle. Prove that AB + CD = AD + BC

Discussion

24.	47. The angles of quadrilateral are in ratio 3:5:9:13.find all the angles of the quadrilateral
Answer» 47. The angles of quadrilateral are in ratio 3:5:9:13.find all the angles of the quadrilateral

Discussion

25.	7.0.15, 0.015, 0.0015,... 20 terms.
Answer» 7.0.15, 0.015, 0.0015,... 20 terms.

Discussion

26.	A hemispherical bowl is made of steel, 0.25 cm thick.The inner radius of the bowl is 5 cm. Find the outer curved surface area of the bowl. [Assume π=227]
Answer» A hemispherical bowl is made of steel, 0.25 cm thick.The inner radius of the bowl is 5 cm. Find the outer curved surface area of the bowl. $[A s s u m e π = \frac{22}{7}]$

Discussion

27.	ntIf a,b,c be the p th, q th, r th term of an A.P. resp., then show thatn nta(q-r)+b(r-p)+c(p-q)=0n
Answer» ntIf a,b,c be the p th, q th, r th term of an A.P. resp., then show thatn nta(q-r)+b(r-p)+c(p-q)=0n

Discussion

28.	Prove the following trigonometric identities.cosec θ1-cos2 θ=1
Answer» Prove the following trigonometric identities. $cosec θ \sqrt{1 - \cos^{2} θ} = 1$

Discussion

29.	For what values of k are the points A(8, 1), B(3, −2k) and C(k, −5) collinear? [CBSE 2015]
Answer» For what values of k are the points A(8, 1), B(3, −2k) and C(k, −5) collinear? [CBSE 2015]

Discussion

30.	In a circle of radius 'r' and center 'O', P and Q are points on the circle such that OP ⊥ OQ. Suppose PQ = a = 1√2. Find PQ in terms of a and r. __
Answer» In a circle of radius 'r' and center 'O', P and Q are points on the circle such that OP $⊥$ OQ. Suppose PQ = a = $\frac{1}{\sqrt{2}}$ . Find PQ in terms of a and r. __

30.

In a circle of radius 'r' and center 'O', P and Q are points on the circle such that OP ⊥ OQ. Suppose PQ = a = 1√2. Find PQ in terms of a and r. __

Answer»

In a circle of radius 'r' and center 'O', P and Q are points on the circle such that OP $⊥$ OQ.

Suppose PQ = a = $\frac{1}{\sqrt{2}}$ . Find PQ in terms of a and r.

__

Discussion

31.	If one root of the equation 2x2+ax+6=0 is 3, then the value of a is ___________.
Answer» If one root of the equation $2 x^{2} + a x + 6 = 0$ is 3, then the value of a is ___________.

Discussion

32.	Find the the roots of −3x2+5x+12=0 by using the quadratic formula.
Answer» Find the the roots of $- 3 x^{2} + 5 x + 12 = 0$ by using the quadratic formula.

Discussion

33.	The height of a cone is 10 cm. The cone is divided into two parts using a plane parallel to its base at the middle of its height. Find the ratio of the volumes of the two parts.
Answer» The height of a cone is 10 cm. The cone is divided into two parts using a plane parallel to its base at the middle of its height. Find the ratio of the volumes of the two parts.

Discussion

34.	In the given figure, PA and PB are two tangents to the circle with centre O. If ∠ APB = 50o then what is the measure of ∠ OAB.
Answer» In the given figure, PA and PB are two tangents to the circle with centre O. If $∠$ APB = $50^{o}$ then what is the measure of $∠$ OAB.

34.

In the given figure, PA and PB are two tangents to the circle with centre O. If ∠ APB = 50o then what is the measure of ∠ OAB.

Answer»

In the given figure, PA and PB are two tangents to the circle with centre O. If $∠$ APB = $50^{o}$ then what is the measure of $∠$ OAB.

Discussion

35.	working together Pratap and ramesh can paint the apartment in 2 days .Working alone, Pratap can complete the job in 3 days less than ramesh.how long it will take each person working alone
Answer» working together Pratap and ramesh can paint the apartment in 2 days .Working alone, Pratap can complete the job in 3 days less than ramesh.how long it will take each person working alone

Discussion

36.	The angle of elevation of the top of a tower at a point on the ground is 45º. After moving a distance of 100 m towards the foot of the tower, the angle of elevation of the top of the tower is found to be 60º. The height of the tower is
Answer» The angle of elevation of the top of a tower at a point on the ground is 45º. After moving a distance of 100 m towards the foot of the tower, the angle of elevation of the top of the tower is found to be 60º. The height of the tower is

Discussion

37.	If ABCD is a cyclic quadrilateral with AB as the diameter of the circle and ∠ACD=50∘, then ∠BAD = ___ degrees.40
Answer» If ABCD is a cyclic quadrilateral with AB as the diameter of the circle and $∠ A C D = 50^{\circ},$ then $∠ B A D$ = ___ degrees. 40

Discussion

38.	Question 12If x+1 is a factor of the polynomial 2x2+kx, then the value of k isA) -3B) 4C) 2D) -2
Answer» Question 12 If x+1 is a factor of the polynomial $2 x^{2} + k x$ , then the value of k is A) -3 B) 4 C) 2 D) -2

Discussion

39.	If the value of secθ=52 what is the value of cosθ?
Answer» If the value of $sec θ = \frac{5}{2}$ what is the value of $cos θ$ ?

Discussion

40.	In the given figure, the incircle of △ABC touches the sides AB, BC and CA at the points P, Q, R respectively. Show that AP+BQ+CR=BP+CQ+AR =12 (Perimeter of △ABC) [3 MARKS]
Answer» In the given figure, the incircle of $△ A B C$ touches the sides AB, BC and CA at the points P, Q, R respectively. Show that $A P + B Q + C R = B P + C Q + A R$ $= \frac{1}{2} (P e r i m e t e r o f △ A B C)$ [3 MARKS]

40.

In the given figure, the incircle of △ABC touches the sides AB, BC and CA at the points P, Q, R respectively. Show that AP+BQ+CR=BP+CQ+AR =12 (Perimeter of △ABC) [3 MARKS]

Answer»

In the given figure, the incircle of $△ A B C$ touches the sides AB, BC and CA at the points P, Q, R respectively. Show that
$A P + B Q + C R = B P + C Q + A R$
$= \frac{1}{2} (P e r i m e t e r o f △ A B C)$
[3 MARKS]

Discussion

41.	From each corner of a square of side 4 cm a quadrant of a circle of radius 1 cm is cut and also a circle of diameter 2 cm is cut as shown in the given figure. Find the area of the remaining portion of the square.
Answer» From each corner of a square of side 4 cm a quadrant of a circle of radius 1 cm is cut and also a circle of diameter 2 cm is cut as shown in the given figure. Find the area of the remaining portion of the square.

41.

From each corner of a square of side 4 cm a quadrant of a circle of radius 1 cm is cut and also a circle of diameter 2 cm is cut as shown in the given figure. Find the area of the remaining portion of the square.

Answer»

From each corner of a square of side 4 cm a quadrant of a circle of radius 1 cm is cut and also a circle of diameter 2 cm is cut as shown in the given figure. Find the area of the remaining portion of the square.

Discussion

42.	find the geometric mean of first five terms of a geometric progression whose nth term is 2.3^n/5
Answer» find the geometric mean of first five terms of a geometric progression whose nth term is 2.3^n/5

Discussion

43.	A fez, the cap used by the Turks, is shaped like the frustum of a cone (see the figure given below). If its radius on the open side is 10 cm, radius at the upper base is 4 cm and its slant height is 15 cm, find the area of material use for making it.
Answer» A fez, the cap used by the Turks, is shaped like the frustum of a cone (see the figure given below). If its radius on the open side is 10 cm, radius at the upper base is 4 cm and its slant height is 15 cm, find the area of material use for making it.

43.

A fez, the cap used by the Turks, is shaped like the frustum of a cone (see the figure given below). If its radius on the open side is 10 cm, radius at the upper base is 4 cm and its slant height is 15 cm, find the area of material use for making it.

Answer»

A fez, the cap used by the Turks, is shaped like the frustum of a cone (see the figure given below). If its radius on the open side is 10 cm, radius at the upper base is 4 cm and its slant height is 15 cm, find the area of material use for making it.

Discussion

44.	7. If 7 cosec A - 3 cot A = 7 , prove that 7 cot A - 3 cosec A = 3.
Answer» 7. If 7 cosec A - 3 cot A = 7 , prove that 7 cot A - 3 cosec A = 3.

Discussion

45.	A solid right circular cone is cut into two parts at the middle of its height by a planeparallel to its base. The ratio of the volume of the smaller cone to the whole cone is(a) 1 : 2(b) 1 : 4(c) 1 : 6(d) 1 : 8
Answer» A solid right circular cone is cut into two parts at the middle of its height by a planeparallel to its base. The ratio of the volume of the smaller cone to the whole cone is (a) 1 : 2 (b) 1 : 4 (c) 1 : 6 (d) 1 : 8

Discussion

46.	Write the arithmetic progression when first term a and common difference d are as follows:(i) a = 4, d = −3(ii) a = −1, d = 12(iii) a = −1.5, d = −0.5
Answer» Write the arithmetic progression when first term a and common difference d are as follows: (i) a = 4, d = −3 (ii) a = −1, d = $\frac{1}{2}$ (iii) a = −1.5, d = −0.5

Discussion

47.	29. Let {x} and [x] denote fractional and integral part of a real number x. The value(s) of x satisfying 4{x} = x + [x] is/are A) 0 B) 5/3 C) 1/3 D) 1
Answer» 29. Let {x} and [x] denote fractional and integral part of a real number x. The value(s) of x satisfying 4{x} = x + [x] is/are A) 0 B) 5/3 C) 1/3 D) 1

Discussion

48.	A die is tossed thrice.Find the probability of getting an odd number at least once.
Answer» A die is tossed thrice.Find the probability of getting an odd number at least once.

Discussion

49.	There is a number x such that x2 is irrational but x4 is rational. Then, x can be(a) 5(b) 2(c) 23(d) 24
Answer» There is a number x such that x² is irrational but x⁴ is rational. Then, x can be (a) $\sqrt{5}$ (b) $\sqrt{2}$ (c) $\sqrt[3]{2}$ (d) $\sqrt[4]{2}$

Discussion

50.	Which of the following is not a quadratic equation?
Answer» Which of the following is not a quadratic equation?

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Match the following to their roots.

The distance between the points P(3, 2) and Q(–4, 5) is

In racing over a given dis†an ce d at uniform speed, A can beat B by 30 meters,B can beat C by 20 meters and A can beat C by 48 meters.Find 'd' in meters.

Which of the following expression gives the value of "s". "s" is given as 12+22+32+42+................+72

In the given figure, ABCD is a trapezium with AB || DC, AB = 18 cm DC = 32 cm and the distance between AB and DC is 14 cm. Circles of equal radii 7 cm with centres A, B, C and D have been drawn. Then find the area of the shaded region.(Use π=227 [CBSE 2014]

A cubical vessel of height 1m is full of water. The minnimum work in taking water out from vessel will be, 1. 5000J 2. 10000 J 3. 5 J 4. 10 J

Show that each of the progressions given below is an AP. Find the first term, common difference and next term of each.(i) 9, 15, 21, 27, ...(ii) 11, 6, 1, −4, ...(iii) −1, -56, -23, -12, ...(iv) 2, 8, 18, 32, ...(v) 20, 45, 80, 125, ...

If the vertices of a triangle are (2,0) (0,2) (4,6), then the equation of the median through the vertex (2,0) is

If cotA+1cotA=2, find the value of cot2A+1cot2A.

What is the value of sin θ×cosec θ×cot θ= ?

Factorize √3 x2 + 5x + 2√3 = 0 by splitting the middle term and find the value of x.

Divya and Dev jointly started a food cart business by investing Rs. 20,000 and Rs. 40,000. After 5 months Divya invested Rs. 10,000 more in the business but Dev withdrew Rs. 20,000. At the end of the year, if the profit of the business is Rs. 1,30,000, what is the profit earned by Divya?

143. Z=(1+i)(1-i)/ (2+i) fibd log z

The value of x+y+z is 15 if a,x,y,z,b are in A.P. while the value of 1x+1y+1z is 53 if a,x,y,z,b are in H. P. Then the value of and b are

A cylindrical vessel with internal diameter 10 cm and height 10.5 cm is full of water. A solid cone of base diameter 7 cm and height 6 cm is completely immersed in water. Find the volume of water (i) displaced out of the cylinder (ii) left in the cylinder.

If A={1,2,3,4,5,6}, B={1,2}, then A-(A-B) is equal to

A square of side 5 centimetres and four isosceles triangles, each of one side 5 centimetres and the height to the opposite vertex 8 centimetres; these are to be joined to make a square pyramind. How much paper is needed for the job?

If 512 is as much as 16 times 32, then it can be represented using the equation

The height of water level in a circular well is 7 m and its diameter is 10 m. Calculate the volume of water stored in the well.

Prove that the points (2, 3), (7, 5), (9, 8), (4, 6) are the vertices of a parallelogram.

f(x)=x^2 + x + 1 how to show that it is an one one function or not

The total surface area of hollow cylinder having the inner and outer radii as R2 and R is xπR(R+L4). Find x.3

Prove that the lengths of tangents drawn from an external point to a circle are equal. Using the above, prove the following:A quadrilateral ABCD is drawn to circumscribe a circle. Prove that AB + CD = AD + BC

47. The angles of quadrilateral are in ratio 3:5:9:13.find all the angles of the quadrilateral

7.0.15, 0.015, 0.0015,... 20 terms.

A hemispherical bowl is made of steel, 0.25 cm thick.The inner radius of the bowl is 5 cm. Find the outer curved surface area of the bowl. [Assume π=227]

ntIf a,b,c be the p th, q th, r th term of an A.P. resp., then show thatn nta(q-r)+b(r-p)+c(p-q)=0n

Prove the following trigonometric identities.cosec θ1-cos2 θ=1

For what values of k are the points A(8, 1), B(3, −2k) and C(k, −5) collinear? [CBSE 2015]

In a circle of radius 'r' and center 'O', P and Q are points on the circle such that OP ⊥ OQ. Suppose PQ = a = 1√2. Find PQ in terms of a and r. __

If one root of the equation 2x2+ax+6=0 is 3, then the value of a is ___________.

Find the the roots of −3x2+5x+12=0 by using the quadratic formula.

The height of a cone is 10 cm. The cone is divided into two parts using a plane parallel to its base at the middle of its height. Find the ratio of the volumes of the two parts.

In the given figure, PA and PB are two tangents to the circle with centre O. If ∠ APB = 50o then what is the measure of ∠ OAB.

working together Pratap and ramesh can paint the apartment in 2 days .Working alone, Pratap can complete the job in 3 days less than ramesh.how long it will take each person working alone

The angle of elevation of the top of a tower at a point on the ground is 45º. After moving a distance of 100 m towards the foot of the tower, the angle of elevation of the top of the tower is found to be 60º. The height of the tower is

If ABCD is a cyclic quadrilateral with AB as the diameter of the circle and ∠ACD=50∘, then ∠BAD = ___ degrees.40

Question 12If x+1 is a factor of the polynomial 2x2+kx, then the value of k isA) -3B) 4C) 2D) -2

If the value of secθ=52 what is the value of cosθ?

In the given figure, the incircle of △ABC touches the sides AB, BC and CA at the points P, Q, R respectively. Show that AP+BQ+CR=BP+CQ+AR =12 (Perimeter of △ABC) [3 MARKS]

From each corner of a square of side 4 cm a quadrant of a circle of radius 1 cm is cut and also a circle of diameter 2 cm is cut as shown in the given figure. Find the area of the remaining portion of the square.

find the geometric mean of first five terms of a geometric progression whose nth term is 2.3^n/5

A fez, the cap used by the Turks, is shaped like the frustum of a cone (see the figure given below). If its radius on the open side is 10 cm, radius at the upper base is 4 cm and its slant height is 15 cm, find the area of material use for making it.

7. If 7 cosec A - 3 cot A = 7 , prove that 7 cot A - 3 cosec A = 3.

A solid right circular cone is cut into two parts at the middle of its height by a planeparallel to its base. The ratio of the volume of the smaller cone to the whole cone is(a) 1 : 2(b) 1 : 4(c) 1 : 6(d) 1 : 8

Write the arithmetic progression when first term a and common difference d are as follows:(i) a = 4, d = −3(ii) a = −1, d = 12(iii) a = −1.5, d = −0.5

29. Let {x} and [x] denote fractional and integral part of a real number x. The value(s) of x satisfying 4{x} = x + [x] is/are A) 0 B) 5/3 C) 1/3 D) 1

A die is tossed thrice.Find the probability of getting an odd number at least once.

There is a number x such that x2 is irrational but x4 is rational. Then, x can be(a) 5(b) 2(c) 23(d) 24

Which of the following is not a quadratic equation?