Question

There are 45 boys and girls in a class. Given the probability that a boy is chosen is in 4/15
Find the number of girls.​

Answer 1

Let the no. of boys in the class be x

Hence no. of girls in the class is (45-x)

Total no. of students = 45

Probability that a boy is picked = $\frac{x}{45}$

But it is given to us to be $\frac{4}{15}$

Hence,

$\frac{x}{45}$ = $\frac{4}{15}$

15x = 45*4

x = 3*4

x = 12

Therefore no. of girls in the class = 45-12 = 33

HOPE IT HELPS !!