Question

The cube of which of the following rational numbers is
512/2197
1)5/6
2)4/7
3)8/13
4)9/11

Answer 1

Answer:

it will be option 3)8/13..

Answer 2

Given:

Consider the given rational number is

512/2197

Find:

Cube root of the number

Solution:

Let the required rational number is a/b then according to the given condition

$\frac{a^{3}}{b^{3}}$ = $\frac{512}{2197}$

Take cube root of both the sides we have

$\frac{a}{b} =\frac{\sqrt[3]{512}}{\sqrt[3]{2197}}$

$\frac{a}{b}=\frac{8}{13}$

Hence the correct option is (3).