Question

33. The boys and girls in a college are in the ratio 3:2. If 20% of the boys and 25% of the girls are adults, the
percentage of students who are not adults is :
(A) 58%
(B) 67.50%
(C) 78%
(D) 82.50%
​

Answer 1

Answer:

Let the number of boys and girls be 3x and 2x respectively

Then,

Number of boys and girls who are adults

=20% of 3x+25% of 2x=(20100×3x)+(25100×2x)=35x+x2=11x10

∴ Number of boys and girls who are not adults

=[(3x+2x)−11x10]=5x−11x10=39x10Requ9ired percentage=(39x10×15x×100)%=78% I hope it will help you