Sonu invested $10 \%$ more than Mona. Mona invested $10 \%$ less than Raghu. If the total sum of their investments is ₹$5,780$,how much amount did Raghu invest?

$a \%$ of $b + b \%$ of $a =$

Mr. Sarang invests $6 \%$ of his monthly salary,i.e.,$Rs.$ $2,100$ on insurance policies. He also invests $8 \%$ of his monthly salary on Family Mediclaim Policies and another $9 \%$ of his salary on $NSCs$. What is the total annual amount invested by Mr. Sarang?

Rice is now being sold at $Rs. 30$ per $kg$. During last month,its rate was $Rs. 26$ per $kg$. Find by how much percentage must a family reduce its consumption to keep the expenditure fixed?

If inflation increases at a rate of $8 \%$ p.a.,what will a $₹ 20$ article cost at the end of two years?

The weights of two iron balls are $3.5 \text{ kg}$ and $7.5 \text{ kg}$. What is the percentage weight of the first ball with respect to the second ball?