Class 8 Maths Chapter 6 Ex 6.2
Question 1.
Find the cube root of each of the following numbers by prime factorisation method.
(i) 64
(ii) 512
(iii) 10648
(iv) 27000
(v) 15625
(vi) 13824
(vii) 110592
(viii) 46656
(ix) 175616
(x) 91125
Solution:
Question 2.
State True or False.
(i) Cube of an odd number is even.
(ii) A perfect cube does not end with two zeros.
(iii) If the square of a number ends with 5, then its cube ends with 25.
(iv) There is no perfect cube which ends with 8.
(v) The cube of a two digit number may be a three digit number.
(vi) The cube of a two digit number may have seven or more digits.
(vii) The cube of a single digit number may be a single digit number.
Solution:
(i) False – Cube of any odd number is always odd, e.g., (7)³ = 343
(ii) True – A perfect cube does not end with two zeros.
(iii) False
(iv) False – (12)³ = 1728 (ends with 8)
(v) False – (10)³ = 1000 (4-digit number)
(vi) False – (99)³ = 970299 (6-digit number)
(vii) True – (2)³ = 8 (1-digit number)
