260 + Interview Questions in Maths in Class 8 Page 3 InterviewSolution

101.	Fill in the blanks:
Answer» Answer :(i) `45^@ and 135^@` (ii) `30^@ and 150^@` (iii) `5 and 108^@ (iv) 8 and 135^@ (V) 12 and 30^@ (VI) 9 and 40^@`

Discussion

102.	If n(A) =a , n(B) = b and the number of subsets of A exceeds number of subsets of B by 1024, then find the values of a and b
Answer» ANSWER :`a=11, B = 10`

Discussion

103.	If the replacement set s={-6,-3,0,3,6,9}, find the truth set of the following : (i) 2x-1 gt 9 (ii) 3x+7 le 1
Answer» ANSWER :(i) {6,9}, (II) {-6,-3}

Discussion

104.	State which of the following are polygons: If the given figure is a polygon, name it as convex or concave.
Answer» ANSWER :CONCAVE

Discussion

105.	State which of the following are polygons: If the given figure is a polygon, name it as convex or concave.
Answer» ANSWER :(II), (ii) and (V).

Discussion

106.	The perimeter of a square, whose each side is 22 cm, is the same as circumference of a circle. Find the area of the circle.
Answer» ANSWER :`616 CM^(2)`

Discussion

107.	Write the Pythagorena triplet whose smallest number is 6 14 16 20
Answer» ANSWER :209

Discussion

108.	Fill in the blanks (i) ((-3)/(17))+((-12)/(5))= ((-12)/(5))+(........) (ii) -9+(-21)/(8)=(......)+(-9) (iii)((-8)/(13)+(3)/(7))+((-13)/(4))=(.......) +[(3)/(7)+((-13)/(4))] (iv)-12+((7)/(12)+(-9)/(11))=(-12+(7)/(12))+(........) (v) (19)/(-5)+((-3)/(11)+(-7)/(8))={(19)/(-5)+(.........)}+(-7)/(8) (vi) (-16)/(7) + ....... = ........ + (-16)/(7)=(-16)/(7)
Answer» ANSWER :`(i)(-3)/(17) (ii) (-21)/(8) (iii) (-8)/(13) (iv) (-9)/(11)(v) (-3)/(11) (vi) 0, 0 `

Discussion

109.	A photograph of a bacteria enlarged 50000 times attains a length of 5 cm. The actual length of bacteria is
Answer» 1000 CM `10^-3` cm `10^-4` cm `10^-2` cm Answer :C

Discussion

110.	The total surface area of a cube is294 cm ^(2)find its volume
Answer» ANSWER :` 343cm ^(3) `

Discussion

111.	Three angles of a quadrilateral are in the ratio 4:6:3. If the fourth angle is 100^@, findthe ther three angles of the quadrilateral.
Answer» `90^@,110^@ and 60^@` `70^@,110^@ and 60^@` `80^@,120^@ and 60^@` `80^@,120^@ and 80^@` ANSWER :C

Discussion

112.	The ratio between the exterior angle and the interior angle of a regular polygon is 1 : 4. Find the number of sides in the polygon.
Answer» ANSWER :10

Discussion

113.	A vertical pole 5 m 60 cm high casts a shadow 3 m 20 cm long. Find at the same time (i) the length of shadown cast by another pole 10 m 50 cm high. (ii) the height of a pole which casts a shadow 5 m long.
Answer» ANSWER :(i) 6 METRES (II) 8 m 75 CM .

Discussion

114.	The totalsurface area of a cyclinder is6512 cm ^(2)and the circumference of its base is88 cm Find (i) its radius (ii)its volume.
Answer» ANSWER :` (i) 14 CM (II)36960 cm ^(3) `

Discussion

115.	Find circumference of the circle, whose area is 24.64 m^(2).
Answer» ANSWER :17.6 m

Discussion

116.	In the following figure, a rectangle ABCDencloses three circles. If BC = 14 cm, find thearea of the shaded portion. (Take api= 3(1)/(7))
Answer» ANSWER :126 `CM^(2)`

Discussion

117.	Evaluate a^(n).
Answer» 64 128 32 256 Solution :(a) EVALUATE `(1^(2)+2^(2)+3^(2))` and express it as the exponent of the SINGLE number. (B) Simplify and get the RESULT.

Discussion

118.	A wire, when bent in the form of a square,encloses an area of 484cm^(2). Find :(i) one side of the square (ii) length of the wire (iii) the largest area enclosed, if the samewire is bent to form a circle.
Answer» ANSWER :(i) 22 cm (ii) 88 cm (III) 616 `cm^(2)`

Discussion

119.	By what least number should the given number me multiplied to get a perfecft square number? In each case, find the number whose square is the new number. 3675 2156 3332 1925 9075 7623 3380 2475 1575 9075 4851 3380 4500 7776 8820 4056
Answer» ANSWER :35

Discussion

120.	There is a path of uniform width 7 m round andoutside a circular garden of diameter 210 m.Find the area of the path.
Answer» ANSWER :`4774 m^(2)`

Discussion

121.	Calculate the compound interest on Rs. 15,000 in 3 years, if the rate of interest for successive years be 6%, 8% and 10% respectively.
Answer» ANSWER :RS. 3,889.20

Discussion

122.	Find the number of sides in a regular polygon, if its interior angle is equal to its exterior angle.
Answer» ANSWER :4

Discussion

123.	Find the radius and circumference of a circle,whose area is :154 cm^(2)
Answer» ANSWER :7 CM and 44 cm

Discussion

124.	Write (T) for true and (F) for false for each of the statements given below: The product of two perfect squares is a perfect square.
Answer» ANSWER :T

Discussion

125.	Find the perimeter of a square whose areais 1.69 m^(2) .
Answer» ANSWER :5.2 m

Discussion

126.	The volume of a cuboid is7.68 m ^(3) if its length =3.2 m and height = 1.0 m : find its breadth.
Answer» ANSWER :` 2.4 m `

Discussion

127.	Two sides of a triangle are 6 cm and 8 cm. Ifheight of the triangle corresponding to 6 cm side is 4 cm, find : (i) area of the triangle (ii) height of the triangle corresponding to8 cm side.
Answer» ANSWER :(i) `12CM^(2)` (II) 3CM

Discussion

128.	Given : In quadrilateral ABCD, angleC= 64^@, angleD= angleC-8^@, angleA=5(a+2)^@ and angleB=2(2a+7)^@. Calculate angleA.
Answer» ANSWER :`130^@`

Discussion

129.	Ajeeta starts off from home at 7 a.m. with her father on a scooter that goes at a uniform speed of 30 km/hr. Her father drops her at her school after half an hour. She stays in the school till 1.30 p.m. and takes an autorikshaw to return home. The autorikshaw has a uniform speed of 10km/hr. Draw the line graph for the given situation and also determine the distance of Ajeeta's school from her home.
Answer» ANSWER :`15KM`

Discussion

130.	Using the rearrangement property find the sum: (i) (4)/(3)+(3)/(5)+(-2)/(3)+(-11)/(5) (ii)(-8)/(3)+(-1)/(4)+(-11)/(6)+(3)/(8) (iii)(-13)/(20)+(11)/(14)+(-5)/(7)+(7)/(10)(iv)(-6)/(7) +(-5)/(6)+(-4)/(9)+(-15)/(7)
Answer» ANSWER :`(i) (-14)/(15) (II) (-35)/(8)(III) (17)/(140)(iv) (-77)/(18) `

Discussion

131.	A cube of edge 6 cmand a cuboidwithdimensions4 cm xx x cm xx 15 cmare equalsin volume . Find: (i)the value of x (ii)total surfacearea of the cuboid (iii)total surface area of the cube. Whichof thesetwo has greater surfaceand byhow much?
Answer» Answer :` 384 CM ^(2)(ii)512 cm ^(3) `

Discussion

132.	Two angles of a quadrilateral are 89^@ and 113^@. If the two angles are equal, find the equal angles.
Answer» ANSWER :`79^@ each`

Discussion

133.	A wall 9 mlong. 6m high and 20 cm thick is to be constructed using bricks of dimensions 30 cm. 15m and 10 cm . How many bricks will be required.?
Answer» ANSWER :` 2400`

Discussion

134.	Calculate the number of sides of a regular polygon, if (i) its interior angle is five times its exterior angle. (ii) the ratio between its exterior angle and interior angle is 2:7. (iii) its exterior angle exceeds its interior angle by 60^@.
Answer» Answer :(i) 12 (II) 9 (iii) 3

Discussion

135.	Find the solutions set of the equations : (i) 12x+6x gt 0, where x is a negative integer. (ii) 30-4(2x-1) lt 30, where x is a positive integer.
Answer» ANSWER :(i) `X GT -2` (II) `x gt 1/2`

Discussion

136.	The perimeter of a rhombus is 40 cm. If onediagnonal is 16 cm, find : (i) its other diagonal (ii) area
Answer» Answer :(i) 12 CM (ii) `96CM^(2)`

Discussion

137.	Divide Rs. 15,600 into two parts such that the interest on one at 5percent for 5 years may be equal to that on the other at 4""1/2 per cent for 6 years.
Answer» ANSWER :RS. 8,100 and Rs. 7,500

Discussion

138.	Name the property of multiplication illustrated by the following statements:(i) (-15)/(8)xx(-12)/(7) = (-12)/(7)xx (-15)/(8)(ii)((-2)/(3) xx (7)/(9)) xx (-9)/(5) = (-2)/(3)xx ((7)/(9)xx (-9)/(5)) (iii) (-3)/(4) xx ((-5)/(6)+(7)/(8))= ((-3)/(4)xx (-5)/(6))+((-3)/(4)xx (7)/(8)) (iv) (-16)/(9) xx 1 = 1 xx (-16)/(9) = (-16)/(9)(v)(-11)/(15)xx (15)/(-11) =(15)/(-11)xx (-11)/(15) = 1 (vi)(-7)/(5) xx 0 =0
Answer» ANSWER :(i) Commutative law (ii)Associative law (III) DISTRIBUTIVE law (iv) PROPERTY of multiplicative IDENTITY (v) Property of multiplicative inverse (vi) Multiplicative property of 0

Discussion

139.	Peter borrows Rs. 12,000 for 2 years at 10% p.a. compound interest. He repays Rs. 8,000 at the end of first year. Find : the amount at the end of first year, after making the repayment.
Answer» ANSWER :RS. 5,230

Discussion

140.	Peter borrows Rs. 12,000 for 2 years at 10% p.a. compound interest. He repays Rs. 8,000 at the end of first year. Find : the principal for the second year.
Answer» ANSWER :RS. 5,200

Discussion

141.	Peter borrows Rs. 12,000 for 2 years at 10% p.a. compound interest. He repays Rs. 8,000 at the end of first year. Find : the amount to be paid at the end of second year, to clear the debt.
Answer» ANSWER :RS. 5,720

Discussion

142.	Peter borrows Rs. 12,000 for 2 years at 10% p.a. compound interest. He repays Rs. 8,000 at the end of first year. Find : the amount at the end of first year, after making the repayment.
Answer» ANSWER :RS. 13, 200

Discussion

143.	The totalsurface area of a cyclinder of diameter 10 cm is330 cm ^(2)Find the height of the cyclinder.
Answer» ANSWER :`5.5 CM `

Discussion

144.	A parallelogram has sides of 15 cm and12 cm. If the distance between the 15 cm sidesis 6 cm, find the distance between 12 cm sides.
Answer» ANSWER :7.5 CM

Discussion

145.	How manypersons can be accommodated in a big - hall of dimensions 40 m . 25m and 15 m.Assuming that each person requires5 m ^(3)of air?
Answer» ANSWER : ` 3000 `

Discussion

146.	Two alternate sides of a regular polygon, when produced, meet at right angle. Calculate the number of sides in the polygon.
Answer» ANSWER :8

Discussion

147.	An exterior angle and an interior angle of a regular polygon are in the ratio 2:7. Find the number of sides in the polygon.
Answer» `8` `7` `10` `9` ANSWER :D

Discussion

148.	Fibonacci numbers Take 10 numbers as shown below: a,b (a+b), (a+2b), (2a+3b), (3a+5b), (5a+8b), (8a+13b), (13a+21b), and (21a+34b). Sum of all these numbers =11(5a+8b) =11 xx 7"th number". Taking a =8, b=13, write 10 Fibonacci numbers and verify that sum of all these numbers =11 xx 7"th number".
Answer» ANSWER :8,13,21,34,55,89,144,233,377,610

Discussion

149.	The sum of the radiusand the height of a cyclinder is 37 cmand the totalsurface areaof the cyclinder is1628 cm ^(2).Find the heightand the volume of the cyclinder.
Answer» ANSWER :30 CMAND ` 4620 CM ^(3)`

Discussion

150.	When twice a non zero positivenumbr is divided by its cube root the quotient is obtained as 32 .If the cube of the number is divided by the number itself then the quotient is ___________
Answer» n/a n/a n/a n/a Answer :`4^(6)`

Discussion

Explore topic-wise InterviewSolutions in .

Fill in the blanks:

If n(A) =a , n(B) = b and the number of subsets of A exceeds number of subsets of B by 1024, then find the values of a and b

If the replacement set s={-6,-3,0,3,6,9}, find the truth set of the following : (i) 2x-1 gt 9 (ii) 3x+7 le 1

State which of the following are polygons: If the given figure is a polygon, name it as convex or concave.

State which of the following are polygons: If the given figure is a polygon, name it as convex or concave.

The perimeter of a square, whose each side is 22 cm, is the same as circumference of a circle. Find the area of the circle.

Write the Pythagorena triplet whose smallest number is 6 14 16 20

A photograph of a bacteria enlarged 50000 times attains a length of 5 cm. The actual length of bacteria is

The total surface area of a cube is294 cm ^(2)find its volume

Three angles of a quadrilateral are in the ratio 4:6:3. If the fourth angle is 100^@, findthe ther three angles of the quadrilateral.

The ratio between the exterior angle and the interior angle of a regular polygon is 1 : 4. Find the number of sides in the polygon.

A vertical pole 5 m 60 cm high casts a shadow 3 m 20 cm long. Find at the same time (i) the length of shadown cast by another pole 10 m 50 cm high. (ii) the height of a pole which casts a shadow 5 m long.

The totalsurface area of a cyclinder is6512 cm ^(2)and the circumference of its base is88 cm Find (i) its radius (ii)its volume.

Find circumference of the circle, whose area is 24.64 m^(2).

In the following figure, a rectangle ABCDencloses three circles. If BC = 14 cm, find thearea of the shaded portion. (Take api= 3(1)/(7))

Evaluate a^(n).

A wire, when bent in the form of a square,encloses an area of 484cm^(2). Find :(i) one side of the square (ii) length of the wire (iii) the largest area enclosed, if the samewire is bent to form a circle.

By what least number should the given number me multiplied to get a perfecft square number? In each case, find the number whose square is the new number. 3675 2156 3332 1925 9075 7623 3380 2475 1575 9075 4851 3380 4500 7776 8820 4056

There is a path of uniform width 7 m round andoutside a circular garden of diameter 210 m.Find the area of the path.

Calculate the compound interest on Rs. 15,000 in 3 years, if the rate of interest for successive years be 6%, 8% and 10% respectively.

Find the number of sides in a regular polygon, if its interior angle is equal to its exterior angle.

Find the radius and circumference of a circle,whose area is :154 cm^(2)

Write (T) for true and (F) for false for each of the statements given below: The product of two perfect squares is a perfect square.

Find the perimeter of a square whose areais 1.69 m^(2) .

The volume of a cuboid is7.68 m ^(3) if its length =3.2 m and height = 1.0 m : find its breadth.

Two sides of a triangle are 6 cm and 8 cm. Ifheight of the triangle corresponding to 6 cm side is 4 cm, find : (i) area of the triangle (ii) height of the triangle corresponding to8 cm side.

Given : In quadrilateral ABCD, angleC= 64^@, angleD= angleC-8^@, angleA=5(a+2)^@ and angleB=2(2a+7)^@. Calculate angleA.

Using the rearrangement property find the sum: (i) (4)/(3)+(3)/(5)+(-2)/(3)+(-11)/(5) (ii)(-8)/(3)+(-1)/(4)+(-11)/(6)+(3)/(8) (iii)(-13)/(20)+(11)/(14)+(-5)/(7)+(7)/(10)(iv)(-6)/(7) +(-5)/(6)+(-4)/(9)+(-15)/(7)

A cube of edge 6 cmand a cuboidwithdimensions4 cm xx x cm xx 15 cmare equalsin volume . Find: (i)the value of x (ii)total surfacearea of the cuboid (iii)total surface area of the cube. Whichof thesetwo has greater surfaceand byhow much?

Two angles of a quadrilateral are 89^@ and 113^@. If the two angles are equal, find the equal angles.

A wall 9 mlong. 6m high and 20 cm thick is to be constructed using bricks of dimensions 30 cm. 15m and 10 cm . How many bricks will be required.?

Calculate the number of sides of a regular polygon, if (i) its interior angle is five times its exterior angle. (ii) the ratio between its exterior angle and interior angle is 2:7. (iii) its exterior angle exceeds its interior angle by 60^@.

Find the solutions set of the equations : (i) 12x+6x gt 0, where x is a negative integer. (ii) 30-4(2x-1) lt 30, where x is a positive integer.

The perimeter of a rhombus is 40 cm. If onediagnonal is 16 cm, find : (i) its other diagonal (ii) area

Divide Rs. 15,600 into two parts such that the interest on one at 5percent for 5 years may be equal to that on the other at 4""1/2 per cent for 6 years.

Peter borrows Rs. 12,000 for 2 years at 10% p.a. compound interest. He repays Rs. 8,000 at the end of first year. Find : the amount at the end of first year, after making the repayment.

Peter borrows Rs. 12,000 for 2 years at 10% p.a. compound interest. He repays Rs. 8,000 at the end of first year. Find : the principal for the second year.

Peter borrows Rs. 12,000 for 2 years at 10% p.a. compound interest. He repays Rs. 8,000 at the end of first year. Find : the amount to be paid at the end of second year, to clear the debt.

Peter borrows Rs. 12,000 for 2 years at 10% p.a. compound interest. He repays Rs. 8,000 at the end of first year. Find : the amount at the end of first year, after making the repayment.

The totalsurface area of a cyclinder of diameter 10 cm is330 cm ^(2)Find the height of the cyclinder.

A parallelogram has sides of 15 cm and12 cm. If the distance between the 15 cm sidesis 6 cm, find the distance between 12 cm sides.

How manypersons can be accommodated in a big - hall of dimensions 40 m . 25m and 15 m.Assuming that each person requires5 m ^(3)of air?

Two alternate sides of a regular polygon, when produced, meet at right angle. Calculate the number of sides in the polygon.

An exterior angle and an interior angle of a regular polygon are in the ratio 2:7. Find the number of sides in the polygon.

Fibonacci numbers Take 10 numbers as shown below: a,b (a+b), (a+2b), (2a+3b), (3a+5b), (5a+8b), (8a+13b), (13a+21b), and (21a+34b). Sum of all these numbers =11(5a+8b) =11 xx 7"th number". Taking a =8, b=13, write 10 Fibonacci numbers and verify that sum of all these numbers =11 xx 7"th number".

The sum of the radiusand the height of a cyclinder is 37 cmand the totalsurface areaof the cyclinder is1628 cm ^(2).Find the heightand the volume of the cyclinder.

When twice a non zero positivenumbr is divided by its cube root the quotient is obtained as 32 .If the cube of the number is divided by the number itself then the quotient is ___________