Question

What should be subtracted from $\frac{-7}{8}$ so as to get $\frac{5}{12}$?

• A. $\frac{31}{24}$
• B. $\frac{8}{5}$
• C. $\frac{-31}{24}$
• D. $\frac{-6}{8}$

Answer 1

Answer: (C)

$\frac{-31}{24}$

Let the number be $x$ to be subtracted from $\frac{-7}{8}$ to get $\frac{5}{12}$. Then it can be solved as follows:

$\frac{-7}{8}-x=\frac{5}{12}\Rightarrow -\frac{7}{8}-x=\frac{5}{12}\Rightarrow x=-\frac{7}{8}-\frac{5}{12}\Rightarrow x=-\frac{7\times 3}{8\times 3}-\frac{5\times 2}{12\times 2}$

$\Rightarrow x=-\frac{21}{24}-\frac{10}{24}\Rightarrow x=\frac{-21-10}{24}\Rightarrow x=-\frac{31}{24}$

Hence, $x=-\frac{31}{24}$