Question

Question 14
The multiplicative inverse of $-1\frac{1}{7}$ is
(a) $\frac{8}{7}$
(b) $\frac{-8}{7}$
(c) $\frac{7}{8}$
(d) $\frac{-7}{8}$

Answer 1

We know that the product of a number with its multiplicative inverse is 1.
Given number is $-1\frac{1}{7}$ , i.e. $\frac{-8}{7}$ then multiplicative inverse is $x$.
$\Rightarrow \frac{-8}{7}\times x=1$
$\Rightarrow x=1\times \left(\frac{-7}{8}\right)$ [by cross-multiplication]
$=\frac{-7}{8}$ or $\frac{7}{-8}$
Hence, $\frac{-7}{8}$ is the multiplicative inverse of $\frac{-8}{7}$ i.e option (d).