Question

The ratio of girls to boys in a movie school is 5:6, on a rainy day 1/6 of girls and 1/4 of boys were absent. If total number of pupils present that day was 390. How many of the pupils were boys.

Answer 1

Let number of girls in the school are $5x$ .Then number of boys are $6x.$

On the rainy day $\frac {1}{6}$ of girls and $\frac{1}{4}$ of boys were absent. Therefore $\frac{5}{6}$ of girls and $\frac{3}{4}$ of boys are present.

So number of girls present on that day are $=5x×(\frac{5}{6})=\frac{25x}{6}$

and number of boys present on that day are $=6x×(\frac{3}{4})=\frac{9x}{2}$

Therefore according to the problem, $\frac{25x}{6}+\frac{9x}{2}=390$

$\implies \frac{52x}{6}=390$

$\implies x=45$

$\therefore$ Number of pupils were boys are $=6x=6×45=270$ .