Question

Question 10
The number of boys and girls in a class are in the ratio7:5.The number of boys is 8 more than the number of girls. What is the total class strength?

Answer 1

Let the number of girls be x.
Then, the number of boys = x+8
According to the question,
$\frac{x+8}{x}=\frac{7}{5}$
$\Rightarrow 5(x+8)=7x$
$\Rightarrow 5x+40=7x$
$\Rightarrow 5x-7x=-40$ [Transposing 7 x to L.H.S. and 40 to R.H.S.]
$\Rightarrow -2x=-40\Rightarrow \frac{-2x}{-2}=\frac{-40}{-2}$[Dividing both sides by -2]
$\Rightarrow x=20$
Hence the number of girls =20 and number of boys = 20+ 8 = 28.
Total class strength =48 students