Question

If $\sqrt[3]{32744}=2p+2$, find the value of p?

• A. 6

Answer 1

The correct option is A 6
By estimation method, grouping three numbers from the right,
$2\underset{–}{744}$
Units digit of the first group is 4. So the units digit of the cube root will be 4
The second group has 2 and the only cube number less than 2 is 1.
So the tens digit of the cube root will be 1.

$\Rightarrow \sqrt[3]{32744}=14$

Given, $\sqrt[3]{32744}=2p+2$
$⟹$ $2p+2=142p=14-2=12$

$\therefore p=\frac{12}{2}=6$