If 20% of A=50% of B, what percentage of A is B ? · ABC26GN2331

20\% of $A=50 \%$ of $B \Rightarrow \frac{20}{100} \times A=\frac{50}{100} \times B$ $$\Rightarrow \frac{A}{5}=\frac{B}{2} \Rightarrow B=\frac{2 A}{5} .$$ Required percentage $=\left(\frac{B}{A} \times 100\right) \%$ $$=\left(\frac{2 A}{5} \times \frac{1}{A} \times 100\right) \%=40 \% .$$