There is a profit of $20 \%$ on the cost price of an article. The per cent of profit, when calculated on the selling price is.......$\%$

Two discounts of $40 \%$ and $20 \%$ are equal to a single discount of what percentage?

$20 \%$ loss on selling price is what per cent loss on the cost price? (in $\%$)

$A$ man bought $500$ metres of electronic wire at $50$ paise per metre. He sold $50 \%$ of it at a profit of $5 \%$. At what percent should he sell the remainder so as to gain $10 \%$ on the whole transaction?

Instead of dividing $391$ cookies among $3$ children $A, B, C$ in the ratio $\frac{1}{5}: \frac{1}{4}: \frac{1}{8}$,they were divided in the ratio $5: 4: 8$. Who gains the most and how many?

By selling an article for $Rs. 384$,a trader gains $20 \%$. Find the cost price of the article.