My father distributed Rs.280 in such a way that each girl received Rs.20 and each boy Rs.10. If the number of boys is less than that of girls by 2, find the number of boys?

Concept Used:-

Substitution method is one of the method to solve the linear equations of two variable. In this, the value of one variable in terms of other variable is putted in the second equation to find the values of variables.

Explanation:-

Suppose, total boys = x

Total girls = y

Given that, the number of boys is less than that of girls by 2. So,

⇒ x = y - 2

⇒ y = x + 2          .....(1)

Here, total money is Rs.280 where each girl received Rs.20 and each boy Rs.10. So,

⇒ 10x + 20y = 280

Put the value of y from equation (1),

⇒ 10x + 20(x + 2) = 280

⇒ 10x + 20x + 40 = 280

⇒ 30x = 280 - 40

⇒ x = 240 / 30

⇒ x = 8

So, the total number of boys is 8.

Hence, the correct option is 1.