Cubes and Cube Roots | Cubes and Cube Roots Exercise 4D

Question

$\sqrt[3]{(125\times64)=?}$

a) 100

b) 40

c) 20

d) 30

Accepted Answer

Firstly we have to find the prime factors of 125

125 = 5 × 5 × 5

And the prime factors of 64

64 = 2 × 2 × 2 × 2 × 2 × 2

$\sqrt[3]{(125\times64)}=\sqrt[3]{(5\times5\times5\times4\times4\times4)}=\sqrt[3]{(5\times5\times5)\times\sqrt[3]{(4\times4\times4)}}$

= 5 × 4 = 20

∴ 20 is the correct answer.

Question 7