Question

The duplicate ratio of $\frac{2}{5}$ is _____

• A. $\frac{4}{10}$
• B. $\frac{4}{25}$
• C. $\frac{7}{5}$
• D. $\frac{8}{125}$

Answer 1

Answer: (B)

$\frac{4}{25}$

If a: b is a ratio, then its duplicate ratio is $\frac{a^2}{b^2}$

therefore duplicate ratio is

ratio $=$ $\frac{2\times 2}{5\times 5}$=$\frac{4}{25}$