Cubes and Cube Roots (Practice Sheet, Class 8)

(1) Which of the following number is not a perfect cube?

(i) 172 (ii) 343

Solution-

(2) Find the smallest number by which 126 must be multiplied to obtain a perfect cube.

Solution-

(3) Find the smallest numbers by which 432 must be divided to obtain a perfect cube.

Solution-

(4) Find the cube root of 32768 by prime factorisation.

Solution-

(5) Guess the cube root of 97336.

Solution-

(6) State true or false.

(i) Cube of 1 is 1.

(ii) Cube of any even number is even.

(iii) A perfect cube has prime factor in triplets.

Solution-

Choose the correct answer.

(7) Hardy – Ramanujan Number is

(i) 1728

(ii) 1727

(iii) 1729

Solution-

(8) What is the number whose cube and cube roots are same?

(i)2

 (ii)3

(iii)1

Solution-

(9) How many perfect cubes are there from 1 to 1000?

(i) 100

(ii) 10

(iii) 0

Solution-

(10) Guess cube root of the number 6859.

Solution-

Helping Topics

Cubes and cubes roots

NCERT solutions

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