What percentage of numbers from $1$ to $70$ have squares that end in the digit $1$?

Deepti invests $11 \%$ of her monthly salary,i.e.,$Rs. 5236$ in Fixed Deposits. Later she invests $19 \%$ of her monthly salary on Life Insurance Policies; also she invests another $7 \%$ of her monthly salary on Mutual Funds. What is the total annual amount invested by Deepti?

$0.025$ in terms of rate per cent is:

In a class of $60$ students, $40\%$ can speak only Hindi, $25\%$ can speak only English and the rest of the students can speak both the languages. How many students can speak English?

If a number is increased by $20 \%$ and then reduced by $20 \%$,what is the net change in the number?

$A$ businessman imported laptops worth $Rs$ $210,000$,mobile phones worth $Rs$ $100,000$,and television sets worth $Rs$ $150,000$. He had to pay $10\%$ duty on laptops,$8\%$ on phones,and $5\%$ on television sets. How much total duty (in Rupees) did he have to pay on all items as per the above details?