Question

Mark (✓) against the correct answer
By what number should (−8)⁻¹ be multiplied to get 10⁻¹?

(a) $\frac{4}{5}$
(b) $\frac{-5}{4}$
(c) $\frac{-4}{5}$
(d) none of these

Answer 1

(c) $\frac{-4}{5}$
Let the required number be x.
(−8)^-1 x x = (10)^-1
⇒ $\frac{1}{-8}\times x=\frac{1}{10}$
∴ x = $\frac{1}{10}\times (-8)$ = $\frac{-4}{5}$
Hence, the required number is $\frac{-4}{5}$.