AP EAMCET Engineering 21 Sep 2020 Shift 2 Paper

(a) Let the number of boys and girls in the class are m and n respectively, so according to given informations,
Total marks of boys =40m
and total marks of girls =45n
and total marks of boys and girls =42(m+n)
∴‌‌40m+45n=42(m+n)
⇒‌‌2m=3n⇒‌

m

3

=‌

n

2

=λ
∴‌40m+45n=42(m
⇒‌2m=3n⇒‌

m

3

=‌

n

2

=λ
∴‌m=3λ‌ and ‌n=2λ
So, the percentage of boys in the class is ‌

m

m+n

×100
=‌

3λ

3λ+2λ

×100=‌

3

5

×100=60%