Question

The ratio of the number of boys and girls in a college is 7 : 8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?
A.8 : 9
B.17 : 18
C.21 : 22
D.Cannot be determined

Answer 1

let x be the common ratio
no of boys
$7x (1 20 \div 100) = 8.4x$
no of girls
$8x(110 \div 100) = 8.8x$
then ratio
$8.4x \div 8.8x = 21 \div 22$
or 21:22