Question

David reads 40 pages of a book in 60 minutes. How many pages should he be able to read in 90 minutes if he reads at a constant rate?

Answer 1

The formula for Rate is given below as,

$\text{Rate}=\frac{Volume}{Time}$

If David reads 40 pages of a book in 60 minutes, the rate will be,

$\begin{gathered} \text{Volume}=40\text{pages} \\ \text{Time}=60\min \\ \text{Rate}=\frac{40}{60}=\frac{2}{3} \end{gathered}$

If the rate is constant (i.e he reads at a constant rate), the number of pages he should be able to read in 90 mins will be,

$\begin{gathered} \text{Rate}=\frac{Volume}{Time} \\ \text{Where Rate =}\frac{2}{3} \\ \text{Time=90mins} \\ \frac{2}{3}=\frac{Volume}{90} \\ \text{Crossmultiply} \\ 3\times Volume=2\times90 \\ \text{Divide both sides by 3} \\ \text{Volume}=\frac{2\times90}{3}=60\text{ pages} \end{gathered}$

Hence, he should be able to read 60 pages if he reads at a constant rate.