A student read 30 pages of a science magazine on Monday and $\frac {1}{8}$ of the magazine on Tuesday. He completed the remaining $\frac {1}{4}$ of the magazine on Wednesday. How many pages are there in the magazine?

Solution

Let there be n number of pages,

Then, $n – \left( {30 + \frac{n}{8}} \right) = \frac{n}{4}$

$\therefore n – 30 = \frac{{3n}}{8}$

$\therefore \frac{{5n}}{8} = 30$

$ \Rightarrow \frac{n}{8} = 6$

$ \Rightarrow n = 48$