Question

Question 128
By what numbers should we multiply $\frac{-15}{20}$ so that the product may be $\frac{-5}{7}$?

Answer 1

Let the required number be x
According to the question,
$x\times \frac{-15}{20}=\frac{-5}{7}$
$x=\frac{-5}{7}\times \frac{20}{-15}=\frac{20}{21}$
Hence, the required number is $\frac{20}{21}$