The population of a town was $160000$ three years ago. If it increased by $3 \%$,$2.5 \%$,and $5 \%$ respectively in the last three years,then the present population is:

$A$ district has $64000$ inhabitants. If the population increases at the rate of $2 \frac{1}{2} \%$ per annum,then the number of inhabitants at the end of $3$ years will be...

Suresh gave $40 \%$ of his income to his wife. He gave $25 \%$ of the remaining amount to his son. Of the remaining amount,he spent $60 \%$ on education. Now,the amount with him is $₹ 2700$. What is the amount he gave to his wife?

$A$ boy found the answer for the question "subtract the sum of $\frac{1}{4}$ and $\frac{1}{5}$ from unity and express the answer in decimals" as $0.45$. The percentage of error in his answer was

Suman's project report on 'Development with dignity',consists of $25$ pages,each with $60$ lines and $75$ characters per line. If the number of lines is reduced to $55$ but the number of characters per line is increased to $90$,what is the percentage change in the number of pages? (Assume the number of pages to be a whole number.)

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?