Question

in a class of 40 students the average age of boys is 15 & girls is 14 the no of girals is one fourth of the total no of students what is the difference between total ages of boys and girls​

Answer 1

Answer:-

Let us assume that,

There are x number of boys.

Number of girls = 40 - x.

given that, the number of girls is one fourth of the total number of boys.

Hence, 40 - x = 1/4 *x

40 - x = x/4

After cross multiplication we get,

4(40 - x) = x

160 - 4x = x

160 = x + 4x

5x = 160

x = 160/5

x = 32

Hence, Number of boys = 32

Number of girls = x/4 = 32/4 = 8

And also given that,

Average age of boys = 15

Sum of ages of boys/Number of boys = 15

Sum of ages of boys/32 = 15

Sum of ages of boys = 32*15 => 480

Average age of girls = 14

Sum of ages of girls/Number of girls = 14

Sum of ages of girls/8 = 14

Sum of ages of girls = 14*8 = 112.

Difference between total ages of boys and girls = 480 - 112 => 368.

Hence, the difference between total ages of boys and girls is 368.