Question

The number of boys in a school are twice the number of girls. If the number of boys is 500, then find the number of girls.

Answer 1

Hint: First, we will assume any random variable let say y to be the number of girls. Then it is given that the number of boys are twice that of girls, so we can write it in mathematical form as 2y. It is told that the total number of boys is 500, so we will compare \[2y=500\] . On solving this equation, we will get a value of y which will be the number of girls. Thus, we will get our answer.

Complete step-by-step answer:
Here, we will suppose that the number of girls is some variable y. So, the number of boys will be equal to 2y as it is given that boys are twice the number of girls.
Now, total number of boys are given which is 500. So, on comparing we can write in mathematical form as
\[2y=500\] …………………….(1)
On dividing equation (1) with 2 on both sides, we will get
\[y=\dfrac{500}{2}=250\]
So, here we can say that y is 250 which we assumed to be the number of girls.
Thus, the total number of girls is 250.

Note: Another approach of solving this problem is applying some logic in question. It is given that boys are twice as tall as girls. So, we can write it in mathematical form as \[b=2g\] where b is boys and g is girls. So, we can write \[g=\dfrac{b}{2}\] . Thus, from this we can write that half of 500 is 250 which is the number of girls. No need to consider any variable and then solve it. Directly, we can get answers.