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?
8 : 9
17 : 18
21 : 22
Cannot be determined
Explanation:
Originally, let the number of boys and girls in the college be 7x and 8x respectively.
Their increased number is (120% of 7x) and (110% of 8x).
=>$ ( \dfrac{120}{100} \times 7x) and ( \dfrac{110}{100} \times 8x)$
=> $\dfrac{42x}{5} and \dfrac{44x}{5}$
The required ratio =$ (\dfrac{42x}{5} : \dfrac{44x}{5})$
Originally, let the number of boys and girls in the college be 7x and 8x respectively.
Their increased number is (120% of 7x) and (110% of 8x).
=>$ ( \dfrac{120}{100} \times 7x) and ( \dfrac{110}{100} \times 8x)$
=> $\dfrac{42x}{5} and \dfrac{44x}{5}$
The required ratio =$ (\dfrac{42x}{5} : \dfrac{44x}{5})$