$A$ man gains $15 \%$ by selling a calculator for a certain price. If he sells it at triple the price,then what will be the profit percentage (in $\%$)?

$A$ shopkeeper bought $30 \text{ kg}$ of wheat at the rate of $₹ 45$ per $\text{kg}$. He sold $40\%$ of the total quantity at the rate of $₹ 50$ per $\text{kg}$. Approximately,at what price per $\text{kg}$ should he sell the remaining quantity to make $25\%$ overall profit? (in $₹$)

The cost price of $40$ articles is the same as the selling price of $25$ articles. Find the gain percent. (in $\%$)

$A$ shopkeeper sold an article offering a discount of $5 \%$ and earned a profit of $23.5 \%$. What would have been the percentage of profit earned if no discount had been offered?

$A$ man sold two watches for $Rs. 3750$ each. On one he gained $5 \%$,and on the other,he lost $5 \%$. What was his total gain or loss percentage?

With a $5 \%$ discount on the cost of sugar,a buyer could purchase $2 \text{ kg}$ more sugar for $Rs. 608$. What is the initial selling price of sugar per kg?