The sum of two numbers is $\frac{28}{25}$ of the first number. The second number is what percent of the first (in $\%$)?

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

An empty fuel tank of a car was filled with an ordinary type of petrol. When the tank was one-third empty,it was filled with high-speed petrol. Again,when the tank was one-third empty,it was filled with an ordinary type of petrol. Again,when the tank was one-third empty,it was filled with high-speed petrol. At this time,what was the percentage of high-speed petrol in the tank?

The population of a variety of tiny bushes in an experimental field increased by $10 \%$ in the first year,increased by $8 \%$ in the second year,but decreased by $10 \%$ in the third year. If the present number of bushes in the experimental field is $26730$,then the number of bushes in the beginning was:

If $A$'s income is $25 \%$ less than that of $B$,then how much per cent is $B$'s income more than that of $A$?

The price of a commodity rises from $Rs. 6$ per $kg$ to $Rs. 7.50$ per $kg$. If the expenditure cannot increase,what is the percentage reduction in consumption (in $\%$)?