What percent of Rs. $2650$ is Rs. $1987.50$?

If the price of gold increases by $30 \%$,find by how much the quantity of ornaments must be reduced so that the expenditure may remain the same as before?

$A$ merchant has announced a $25 \%$ rebate on the prices of ready-made garments at the time of sale. If a purchaser needs to have a total rebate of $₹ 400$,then how many shirts,each costing $₹ 320$,should they purchase?

$A$ person scores $45 \%$ of the total marks in the exam and still fails by $40$ marks. The passing percentage of the exam is $55 \%$. What is the maximum marks of the exam?

In a class,$60 \%$ of the students pass in Hindi and $45 \%$ pass in Sanskrit. If $25 \%$ of them pass in both subjects,what percentage of the students fail in both subjects?

If the length and breadth of a rectangular field are increased,the area increases by $50 \%$. If the length is increased by $20 \%$,by what percentage was the breadth increased?