Question

A number increases from $30$ to $40$ and then decreases from $40$ to $30$. Compare the percent of increase from $30$ to $40$ and that of the decrease from $40$ to $30$.

Answer 1

A number increases from $30$ to $40$ that is it increases by $10$

the original number was $30$.

Hence the percentage of increase $=\frac{10}{30}\times 100=33.3333\%\approx 33\%$

When the number decreases ,it decreases by $10$ only but the original number was $40$

Hence the percentage of increase $=\frac{10}{40}\times 100=25\%$