260 + Interview Questions in Maths in Class 8 Page 5 InterviewSolution

201.	The ratio betweenthe curved surface areaand the totalsurfacearea of a cyclinder is 1: 2Find the ratio betweenthe heightand the radiusof the cyclinder.
Answer» ANSWER :` 1: 1`

Discussion

202.	Use the following figure to find the value of x.
Answer» ANSWER :`50^@`

Discussion

203.	Divide line segmentAB=10 cm into six equal parts.
Answer» Solution :step 1`:` Draw `AB=10` cm Step 2`:` Draw a ray AL such that AL does not COINCIDE with AB. Step 3`:` Mark SIX equal line segments AC,CD,DE,EF,FG and GH on the ray AL of some convenient length, using a compass. Step4 `:` Join HB. Step 5 `:` Draw line segments parallel HB, through the points C,D,E,F and G intersecting the line segment AB at P,Q,RR,S and T RESPECTIVELY. The line segments AP,PQ,QR,RS,ST and TBARE the REQUIRED six equal parts of the line segment AB. Dividing a line segment internally in a given ratio

Discussion

204.	Two sides of a triangle are 6.4 m and 4.8 m.If height of the triangle corresponding to 4.8 m side is 6 m, find :(i) area of the triangle, (ii) height of the triangle corresponding to6.4 m side
Answer» ANSWER :(i) `14.4 m^(2)` (II) 4.5 m

Discussion

205.	The perimeter of a square is numerically equalto its area. Find its area.
Answer» ANSWER :16 SQ. UNITS

Discussion

206.	One of the equal sides of an isosceles triangleis 13 cm and its perimeter is 50 cm. Find thearea of the triangle.
Answer» ANSWER :`60 CM^(2)`

Discussion

207.	A pole 14 m high casts a shadow of 10 m. At the same time , what will be the height of a tree, the length of whose shadow is 7 meters?
Answer» 20m 9.8m 5m non of these Answer :B

Discussion

208.	Which of the following numbers is not a perfect square ?
Answer» 3600 6400 2704 3969 Answer :C

Discussion

209.	For each inequation , given below, represent the solution on a number line: 5/2 -2x ge 1/2, x in W
Answer» ANSWER :`X LE 1, x in W ={0,1}` `(##SEL_RKB_ICSE_MAT_VIII_C15_E02_013_A01##)`

Discussion

210.	A room5 m long 4.5 mwide and 3.6mhigh has one door 1.5 mby 2.4mand two windowseach 1m by 0.75m. Find:(i)the area of its walls ,excluding door and windows. (ii)the cost of distempering its walls at the rate of rupees 4.50per m ^(2) (iii)The cost of painting itsroof at the rate of rupees 9 per m ^(2)
Answer» Answer :` 63. 3 m ^(2)(II)284 . 85 (iii)202 . 50 `

Discussion

211.	A cuboid is 8 m long . 12 m broad and 3.5 m high. Find its total surface area.
Answer» ANSWER :` 332 m ^(2) `

Discussion

212.	The sum of interior angles of a regular polygon is twice the sum of its exterior angles. Find the number of sides of the polygon.
Answer» `8` `7` `5` `9` ANSWER :A

Discussion

213.	A circular field of radius 105 m has a circularpath of uniform width of 5 m along and insideits boundary. Find the area of the path.
Answer» ANSWER :`3221(3)/(7) m^(2)`

Discussion

214.	A path of uniform width 2m runs around the inside of a square field of side 20m. Find the area of the path.
Answer» ANSWER :`144 m^(2)`

Discussion

215.	The radiiof the inner and outer circumferences of a circular-running-track are 63 m and 70 m respectively. Find : (i) the area of the track (ii) the difference between the lengths of thetwo circumferences of the track
Answer» ANSWER :(i) `2926 m^(2)` (II) 44 m

Discussion

216.	Explain the situations represented by the following distance-time graphs :
Answer» Answer :`(a)` Uniform speed `(B)` Moves with uniform speed and then comes to REST. `(C )` Moves with nonuniform speed and then SLOWLY comes to rest.

Discussion

217.	The perimeter of a square is 36 cm, find itsarea.
Answer» ANSWER :`81 CM^(2)`

Discussion

218.	Locate the points P(3, 4), Q(1, 0), R(0, 4) and S(4, 1) on a graph sheet and write the coordinates of the point of intersection of line segments PQ and RS.
Answer» ANSWER :(2, 2)

Discussion

219.	Find the capacityof a cyclindercontainerwith internal diameter 28 cm and height20 cm.
Answer» ANSWER :` 12320 CM ^(3)`

Discussion

220.	Calculate the sum of angles of a polygon with : (i) 10 sides (ii) 12 sides (iii) 20 sides
Answer» ANSWER :`(i) 1440^@ (II) 1800^@ (III) 3240^@`

Discussion

221.	Find the samallest number by which 396 must be multiplied so that the product becomes a perfect square.
Answer» ANSWER :`396 = 2XX2 XX 3xx3 xx11.`

Discussion

222.	A solid cube of edge14 cmis melted down and recast into smaller and equal cubes each of edge 2 cm . Find the number of smaller cubes obtained.
Answer» ANSWER :` 343`

Discussion

223.	A roller has a diameter of 1.4 m. Find : (i) its circumference (ii) the number of revolutions it makes whiletravelling 61.6 m.
Answer» ANSWER :(i) 4.4 m (II) 14

Discussion

224.	A closed box is a cuboidin shape with length = 40 cm, breadth= 30 cmand height = 50 cm , It is made of thin metal sheet. Find the cost of metal sheets required to make 20 such boxes. If1m ^(2)of metal sheet costs rupes 45.
Answer» ANSWER :` 846 `

Discussion

225.	A sum of money, lent out at simple interest, doubles itself in 8 years. Find : (i) the rate of interest. (ii) In how many years will the sum become triple (three times) of itself at the same rate percent ?
Answer» Answer :(i) `12*5%`(ii) 16 YEARS

Discussion

226.	Which of the following numbers is in standard form?
Answer» `(-12)/(26)` `(-49)/(70)` `(-9)/(16)` `(28)/(-105)` Answer :C

Discussion

227.	The sum of the interior angles of a regular polygon is equal to six times the sum of exterior angles. Find the number of sides of the polygon.
Answer» ANSWER :`2n=28 and n=14`

Discussion

228.	Find the amount and the compound interest on Rs. 4,000 in 2 years, if the rate of interest for first year is 10% and for the second year is 15%.
Answer» ANSWER :RS. 5,060 and Rs. 1,060

Discussion

229.	A wire, when bent in the form of a square,encloses an area of 196 cm^(2). If the same wireis bent to form a circle, find the area of the circle.
Answer» ANSWER :249.45 `CM^(2)`

Discussion

230.	Find the area of metal - sheet requiredto make an opentank of length= 10 mbreadth= 7.5m and depth = 3.8 m.
Answer» ANSWER :` 208 m^(2)`

Discussion

231.	MN and PS are two equal chords of a circle drawn on either side of centre O of the circle . Both the chords are produced to meet at point A. If the radius of the circle is 10cm. MN=12 cm and OA =17 cm , then find NA.
Answer» ANSWER :9 CM

Discussion

232.	A and B are any two sets. P_(1) is the power set of A and P_(2) is the power set of B. If n(P_(1))-n(P_(2))=31, then find the number of elements in a and B.
Answer» ANSWER :5

Discussion

233.	A rectangular sheet of paper44 cm xx 18 cmis rolledalong its length and a cycllinder is formed. Find the radius and the volume of the cyclinder formed.
Answer» ANSWER :` 2772 CM ^(3)`

Discussion

234.	Draw a line segment of length 8 cm and divides it in the ratio 2: 3
Answer» Solution :Step 1 `:` Draw aline segment AB of length 8 cm. Step 2`:` Draw a ray AP which does not coincide with AB. Step 3 `:` Mark five `(2+3=5)` equal line segmentsAC,CD,DE,EF and FG on the ray AP using a compass. Step 4 `:` JOIN GB. Step 5`:` Through E, draw a line segment parallel to GB to intersect AB at X. `:. `AX and XB are in the ratio `2:3

Discussion

235.	The parallel sides of a trapezium are in theratio 3:4. If the distance between the parallel sides is 9 dm and its area is 126 dm^(2),find thelengths of its parallel sides.
Answer» ANSWER :12 DM and 16 dm

Discussion

236.	Find the area of trianglewhose sides are 9 cm, 12cm and 15 cm. Also, find the length of altitude corresponding to the largest side of the triangle.
Answer» ANSWER :`54CM^(2)` ;7.2 CM

Discussion

237.	If x and y are directly proportional, find the values of x_1,x_2 and y_1 in the table given below:
Answer» ANSWER :`x_1=5,x_2=8,y_1=240`

Discussion

238.	A certain sum amounts to Rs. 3,825 in 4 years and to Rs. 4,050 in 6 years. Find the rate percent and the sum.
Answer» ANSWER :`3""1/3%` and RS. 3,375

Discussion

239.	Consider the following input/output table. Draw a line graph for it. Now, use the graph drawn to predict the outputs for the inputs of 3 and 8.
Answer» ANSWER :`8` and `23` RESPECTIVELY

Discussion

240.	A field is in the shape of a quadrilateral ABCDin which side AB = 18 m, side AD = 24 m,side BC = 40 m, DC = 50 m and angleA=90^(@). Find the area of the field.
Answer» ANSWER :816 `m^(2)`

Discussion

241.	The sides of a pentagon are produced in order. If the measures of exterior angles so obtaineed are x^(@), (2x)^@, (3x)^@, (4x)^@ and (5x)^@, find all the exterior angles.
Answer» Answer :`24^@, 48^@, 72^@, 96^@ and 120^@`

Discussion

242.	How many3 cm cubes can be cut from a cuboidmeasuring18 xx 12 cm xx 9 cm?
Answer» ANSWER :` 72`

Discussion

243.	If n(A) = n(B) = n(C) = 13, n(A nn B nn C') = 2, n(B nn C nn A') = 4, n(A nn C nn B') = 3 and n(A nn B nn C) = 1then find the number of elements which belongs to at most one of the sets.
Answer» ANSWER :18

Discussion

244.	(i) If all the angles of a hexagon are equal, find the measure of each angle. (ii) If all the angles of a 14-sided figure are equal, find the measure of each angle.
Answer» ANSWER :`(i) 120^@ (II) (154""2/7)^2`

Discussion

245.	A man started his journey on his car from location A and came back. The graph given below shows his position at different times during the whole journey. Study the above graph carefully and answer the questions that follow: (i) At what time did he start and end his journey ? (ii) What was the total duration of the journey ? (iii) Which journey, onward or return, was of longer duration? (iv) For how many hours did he not move ? (v) At what time did he have the fastest speed ?
Answer» Answer :`(i) 5.30` a.m., `6` p.m. `(ii) 12` h `30` MIN `(III)` Forward `(IV) 6` HOURS `(v) 2` p.m. to `5.30` p.m.

Discussion

246.	Find the square of 39 by using the diagonal method.
Answer» ANSWER :`THEREFORE (39)^(2) =1521`

Discussion

247.	Observe the tables given below and in each one find whether x and y are proportional:
Answer» ANSWER :YES

Discussion

248.	Is it possible to have a regular polygon with each interior angle equal to 105^@?
Answer» ANSWER :` 4 4/5`

Discussion

249.	Find the area of the circle, length of whosecircumference is equal to the sum of the lengths of the circumferences of circles withradii 15 cm and 13 cm.
Answer» ANSWER :2464 `CM^(2)`

Discussion

250.	The ratio of the number of sides of two polygons is 1:2, and the ratio of the sum of their angles is 3:8. Find the number of sides in each polygon.
Answer» `7` and `19` `5` and `19` `5` and `18` `8` and `11` ANSWER :B

Discussion

Explore topic-wise InterviewSolutions in .

The ratio betweenthe curved surface areaand the totalsurfacearea of a cyclinder is 1: 2Find the ratio betweenthe heightand the radiusof the cyclinder.

Use the following figure to find the value of x.

Divide line segmentAB=10 cm into six equal parts.

Two sides of a triangle are 6.4 m and 4.8 m.If height of the triangle corresponding to 4.8 m side is 6 m, find :(i) area of the triangle, (ii) height of the triangle corresponding to6.4 m side

The perimeter of a square is numerically equalto its area. Find its area.

One of the equal sides of an isosceles triangleis 13 cm and its perimeter is 50 cm. Find thearea of the triangle.

A pole 14 m high casts a shadow of 10 m. At the same time , what will be the height of a tree, the length of whose shadow is 7 meters?

Which of the following numbers is not a perfect square ?

For each inequation , given below, represent the solution on a number line: 5/2 -2x ge 1/2, x in W

A room5 m long 4.5 mwide and 3.6mhigh has one door 1.5 mby 2.4mand two windowseach 1m by 0.75m. Find:(i)the area of its walls ,excluding door and windows. (ii)the cost of distempering its walls at the rate of rupees 4.50per m ^(2) (iii)The cost of painting itsroof at the rate of rupees 9 per m ^(2)

A cuboid is 8 m long . 12 m broad and 3.5 m high. Find its total surface area.

The sum of interior angles of a regular polygon is twice the sum of its exterior angles. Find the number of sides of the polygon.

A circular field of radius 105 m has a circularpath of uniform width of 5 m along and insideits boundary. Find the area of the path.

A path of uniform width 2m runs around the inside of a square field of side 20m. Find the area of the path.

The radiiof the inner and outer circumferences of a circular-running-track are 63 m and 70 m respectively. Find : (i) the area of the track (ii) the difference between the lengths of thetwo circumferences of the track

Explain the situations represented by the following distance-time graphs :

The perimeter of a square is 36 cm, find itsarea.

Locate the points P(3, 4), Q(1, 0), R(0, 4) and S(4, 1) on a graph sheet and write the coordinates of the point of intersection of line segments PQ and RS.

Find the capacityof a cyclindercontainerwith internal diameter 28 cm and height20 cm.

Calculate the sum of angles of a polygon with : (i) 10 sides (ii) 12 sides (iii) 20 sides

Find the samallest number by which 396 must be multiplied so that the product becomes a perfect square.

A solid cube of edge14 cmis melted down and recast into smaller and equal cubes each of edge 2 cm . Find the number of smaller cubes obtained.

A roller has a diameter of 1.4 m. Find : (i) its circumference (ii) the number of revolutions it makes whiletravelling 61.6 m.

A closed box is a cuboidin shape with length = 40 cm, breadth= 30 cmand height = 50 cm , It is made of thin metal sheet. Find the cost of metal sheets required to make 20 such boxes. If1m ^(2)of metal sheet costs rupes 45.

A sum of money, lent out at simple interest, doubles itself in 8 years. Find : (i) the rate of interest. (ii) In how many years will the sum become triple (three times) of itself at the same rate percent ?

Which of the following numbers is in standard form?

The sum of the interior angles of a regular polygon is equal to six times the sum of exterior angles. Find the number of sides of the polygon.

Find the amount and the compound interest on Rs. 4,000 in 2 years, if the rate of interest for first year is 10% and for the second year is 15%.

A wire, when bent in the form of a square,encloses an area of 196 cm^(2). If the same wireis bent to form a circle, find the area of the circle.

Find the area of metal - sheet requiredto make an opentank of length= 10 mbreadth= 7.5m and depth = 3.8 m.

MN and PS are two equal chords of a circle drawn on either side of centre O of the circle . Both the chords are produced to meet at point A. If the radius of the circle is 10cm. MN=12 cm and OA =17 cm , then find NA.

A and B are any two sets. P_(1) is the power set of A and P_(2) is the power set of B. If n(P_(1))-n(P_(2))=31, then find the number of elements in a and B.

A rectangular sheet of paper44 cm xx 18 cmis rolledalong its length and a cycllinder is formed. Find the radius and the volume of the cyclinder formed.

Draw a line segment of length 8 cm and divides it in the ratio 2: 3

The parallel sides of a trapezium are in theratio 3:4. If the distance between the parallel sides is 9 dm and its area is 126 dm^(2),find thelengths of its parallel sides.

Find the area of trianglewhose sides are 9 cm, 12cm and 15 cm. Also, find the length of altitude corresponding to the largest side of the triangle.

If x and y are directly proportional, find the values of x_1,x_2 and y_1 in the table given below:

A certain sum amounts to Rs. 3,825 in 4 years and to Rs. 4,050 in 6 years. Find the rate percent and the sum.

Consider the following input/output table. Draw a line graph for it. Now, use the graph drawn to predict the outputs for the inputs of 3 and 8.

A field is in the shape of a quadrilateral ABCDin which side AB = 18 m, side AD = 24 m,side BC = 40 m, DC = 50 m and angleA=90^(@). Find the area of the field.

The sides of a pentagon are produced in order. If the measures of exterior angles so obtaineed are x^(@), (2x)^@, (3x)^@, (4x)^@ and (5x)^@, find all the exterior angles.

How many3 cm cubes can be cut from a cuboidmeasuring18 xx 12 cm xx 9 cm?

If n(A) = n(B) = n(C) = 13, n(A nn B nn C') = 2, n(B nn C nn A') = 4, n(A nn C nn B') = 3 and n(A nn B nn C) = 1then find the number of elements which belongs to at most one of the sets.

(i) If all the angles of a hexagon are equal, find the measure of each angle. (ii) If all the angles of a 14-sided figure are equal, find the measure of each angle.

Find the square of 39 by using the diagonal method.

Observe the tables given below and in each one find whether x and y are proportional:

Is it possible to have a regular polygon with each interior angle equal to 105^@?

Find the area of the circle, length of whosecircumference is equal to the sum of the lengths of the circumferences of circles withradii 15 cm and 13 cm.

The ratio of the number of sides of two polygons is 1:2, and the ratio of the sum of their angles is 3:8. Find the number of sides in each polygon.