If 20% of A = 50% of B, then what percent of A is B?

Given:

$20%$ of A $= 50%$ of B

$\frac{20}{100}A=\frac{50}{100}B$

$\frac{1}{5}A=\frac{1}{2}B$

Multiply by $10$:

$2A=5B$

$B=\frac{2A}{5}$

$=\frac{2}{5}\times 100%$ of A

$=40%$

Correct Answer: 40%