Question

Solve the word problem.

A school has $8$ periods in a day each of $45$ minutes duration. How long would each period be, if the school has $9$ periods in a day, assuming the number of school hours to be the same?

Answer 1

According to the question,

A school has $8$ periods in a day each of $45$ minutes duration

The number of periods and the duration of periods are in inverse proportion.

$$\begin{gathered} \Rightarrow \frac{8}{9}=\frac{?}{45} \\ \Rightarrow \frac{8\times 45}{9}=40\mathrm{minutes} \end{gathered}$$

Hence, the duration of each period is $40\mathrm{minutes}$.