$40 \%$ of $? = 240$

What is $15$ percent of Rs. $34$?

$A$ student multiplied a number by $\frac{3}{5}$ instead of $\frac{5}{3}$. What is the percentage error in the calculation (in $\%$)?

The price of a shirt is increased by $15 \%$ and then reduced by $15 \%$. The final price of the shirt

The length of a rectangle increases by $20 \%$ and the breadth by $30 \%$. Then the perimeter of the rectangle will increase by:

In an examination,$65 \%$ of students pass in History and $55 \%$ of students pass in Hindi. If $5 \%$ of students fail in both subjects,what is the percentage of students who passed in both subjects?