In a class there are total 63 students. The average age of girls is 24 years and that of boys is 21

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02 Jun 2022 Average

In a class there are total 63 students. The average age of girls is 24 years and that of boys is 21 years. If the average age of whole class is 22 years and 8 months, then number of boys in a class is

OPtion

1) 42
2) 35
3) 36
4) 14
5) 52
6) 48
7) 56
8) 28
9) 44
10) None of these

Solution

Let there be 'x' boys and (63-x) girls in a class.
22 years & 8 months = 22 (8/12) years = 68/3 years
Average age of whole class = [ 21x + (63-x)*24 ] / 63 = 68/3
Solving, we get x=28
.'. Number of boys in a class is 28.

Correct Option: 8 Best Solution (1)