Question

Question 7

In the following question, out of the four options, only one is correct. Write the correct answer:

The reciprocal of ${\left(\frac{2}{5}\right)}^{-1}$ is:
(a) $\frac{2}{5}$

(b) $\frac{5}{2}$

(c) $-\frac{5}{2}$

(d) $-\frac{2}{5}$

Answer 1

Using law of exponents,
$a^{-m}=\frac{1}{a^m}$

$\therefore {\left(\frac{2}{5}\right)}^{-1}=\frac{1}{{\left(\frac{2}{5}\right)}^1}=\frac{5}{2}$