If "basis points" are defined so that $1 \%$ is equal to $100$ basis points,then by how many basis points is $82.5 \%$ greater than $62.5 \%$?

$A$ clerk received an annual salary of $Rs$ $3,660$ in the year $1975$. This was $20\%$ more than his salary in $1974$. What was his salary in $1974$?

An inspector rejects $0.08 \%$ of the meters as defective. How many will he examine to reject $2$?

During one year,the population of a town was increased by $5 \%$ and during the next year,the population decreased by $5 \%$. If the total population is $9975$ at the end of the second year,then what was the population size in the beginning of the first year?

The price of cooking oil has increased by $15 \%$. The percentage of reduction that a family should effect in the use of cooking oil so as not to increase the expenditure on this account is:

If a number multiplied by $25 \%$ of itself gives a number which is $200 \%$ more than the number,then the number is: