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

$A$ spider climbed $62 \frac{1}{2} \%$ of the height of the pole in one hour and in the next hour it covered $12 \frac{1}{2} \%$ of the remaining height. If the height of the pole is $192 \, m$,then the distance climbed in the second hour is:

One side of a square is increased by $30 \%$. To maintain the same area,the other side will have to be decreased by:

If $x \%$ of $y$ is equal to $z,$ what per cent of $z$ is $x$ ?

The population of Delhi two years ago was $55000$. It increased by $12 \%$ in the first year and decreased by $15 \%$ in the second year. What was the population of the town at the end of $2$ years?

If $A = x \%$ of $y$ and $B = y \%$ of $x$,then which of the following is true?