Question

42 student in class 7th if number of girls is 15 if average weight of girls is 45 kg then find the average weight of all student weight of bpys is 52 kg

Answer 1

Let initial no. Of students=x
Avg. Wt. = 60kg
Therefore, total wt. = 60x

Again,
No. Of students= 8
Avg. Wt. = 64kg
Therefore, total wt.= 64*8=512kg

Now, total avg. Wt.=62kg
Total students= x+8
Therefore, total wt. =62*(x+8) = 62x + 496

A/Q
60x + 512= 62x+496
-› 512-496 = 62x - 60x
-›2x=16
-› x =16/2 = 8

Therefore, initial no. Of students=x=8