# Cubes and Cube Roots MCQ Questions Class 8 Maths Chapter 7

Cubes and Cube Roots MCQ Questions Class 8 Maths Chapter 7

NCERT MCQ Questions for Class 8 Maths Chapter 7 Cubes and Cube Roots. Cubes and Cube Roots MCQ Questions with Answers from Class 8 Maths.

## Cubes and Cube Roots MCQ Questions Class 8 Maths Chapter 7

Cubes and Cube Roots Multiple Choice Questions with Answers Class 8 Maths Chapter 7 PDF is available.

Question 1:

Find the cube root of 729.

(a) 9

(b) 10

(c) 11

(d) 7

Ans:

Prime factorisation of 729 = 3×3×3×3×3

3×3 = 9

(a) 3√729 = 9

Question 2:

Find the cube root of 15625

(a) 35

(b) 45

(c) 25

(d) 15

Ans:

3√15625 = 5×5×5×5×5×5

= 5×5

3√15625 = 25 (c)

Question 3:

Find the cube root of 2197

(a) 23

(b) 13

(c) 14

(d) 15

Ans:

Prime factorisation of 2197 = 13×13×13

3√2197 = 13 (b)

Question 4:

Find the cube root of 1000

(a) 100

(b) 15

(c) 20

(d) 10

Ans:

3√1000 = 5×2×5×2×5×2

= 5×2 = 10 (d)

Question 5:

Find 3√3375 =?

(a) 15

(b) 16

(c) 17

(d) 18

Ans:

3√3375 = 15 (a)

3375 = 5×3×5×3×5×3

= 5×3 = 15

Question 6:

Which of the following no. are not perfect cube?

(a) 333

(b) 1128

(c) 1331

(d) 729

Ans:

(a) 333 = 3×111

The primes 3 and 111 do not appear in groups of three so 333 is not a perfect cube

Question 7:

2744 is the perfect cube?

(a) Yes

(b) No

(c) May be

(d) May not be

Ans:

(a) Yes, 2744 = 7×2×7×2×7×2

3√2744 = 14

Question 8:

Find the smallest no by which 81 must be divided to obtain perfect cube

(a) 4

(b) 3

(c) 2

(d) 9

Ans:

(b) 3, 81/3 = 27 = 3×3×3

√27 = 3

Question 9:

Find the smallest number by which 72 must be multiplied to obtain a perfect cube?

(a) 3

(b) 4

(c) 2

(d) 5

Ans:

(a) 3, 72 × 3 = 216 = 3×2×3×2×3×2

3√216 = 6

Question 10:

Find the 3√125 =?

(a) 3

(b) 6

(c) 5

(d) 15

Ans:

(c) 5 = 125 = 5×5×5

3√125 = 5

Question 11:

Find the cube root of 4913

(a) 15

(b) 17

(c) 13

(d) 14

Ans:

4916 = 17×17×17

3√4913 =17 (b)

Question 12:

Find the cube of 18

(a) 5831

(b) 6859

(c) 5832

(d) 6831

Ans:

18×18×18 = 324×18

183 = 5832 (c)

Question 13:

Find the cube of 8

(a) 612

(b) 516

(c) 729

(d) 512

Ans:

8×8×8 = 512

83 = 512 (a)

Question 14:

Find the cube root of 6859

(a) 17

(b) 13

(c) 16

(d) 19

Ans:

6859 = 19×19×19

3√6859 = 19 (d)

Question 15:

Which are not perfect cube?

(a) 729

(b) 1331

(c) 1728

(d) 2000

Ans:

(d) 2000 is not perfect cube because

2000 = 2×5×2×5×2×5×2

Prove 2 do not appear in group of three.

Updated: April 11, 2023 — 12:25 pm