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
- In case you have missed:- Previous Chapter MCQ Questions
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.
- In case you have missed:- Next Chapter MCQ Questions