$A$ number,when $35$ is subtracted from it,reduces to its $80$ percent. What is four-fifths of that number?

The population of a town increases by $2.5 \%$ annually but decreases by $0.5 \%$ every year due to migration. What will be the net percentage increase in population after $2$ years (in $\%$)?

The product of one-third of a number and $150 \%$ of another number is what percent of the product of the given numbers?

$A$ fruit seller had some apples. He sells $40 \%$ of the apples and still has $420$ apples. Originally,how many apples did he have?

$3.5$ can be expressed in terms of percentage as:

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