$A$ sold a pen to $B$ at a profit of $20\%,$ $B$ sold the same pen to $C$ for $Rs.\,75$ thereby making a profit of $25 \% .$ Find the price at which $A$ bought the pen? (in $Rs.$)

The marked price of a piano was $Rs. 15,000$. At the time of sale,there were successive discounts of $20\%$,$10\%$,and $10\%$ on it. The sale price was (in $Rs.$)

$A$ man invests $Rs. 21,000$ in shares of a company. He sells one-third of the total shares at a profit of $10\%$. However,he has to sell the remaining shares at a $5\%$ loss. Find his overall profit or loss percentage.

Anil bought an item with $12 \frac{1}{2} \%$ discount on the labelled price. He sold the item with $17 \frac{1}{2} \%$ profit on the labelled price. What was his percent profit on the price he bought?

$A$ sells a bicycle to $B$ at a profit of $20 \%.$ $B$ sells it to $C$ at a profit of $25 \%.$ If $C$ pays $Rs. 225$ for it,the cost price of the bicycle for $A$ is (in $Rs.$)

If the cost price of $20$ tables is equal to the selling price of $25$ tables,find the loss percentage. (in $\%$)