There are 48 students in a college gathering. The ratio of the number of boys to the number of girls in the gathering is 5 : 3. If the ratio of the boys to girls has to be made 6 : 5, then how many girls need to be added to the gathering, without changing the numbers of boys who are attending the gathering?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 7
The number of boys stays the same, so the boys are found from the first ratio and the girls needed are found from the new ratio with the same number of boys.
Boys \(\displaystyle =\frac{5}{8}\times48=30\); girls \(=48-30=18\)
For boys : girls \(=6:5\) with 30 boys, girls \(\displaystyle =30\times\frac{5}{6}=25\)
Girls to be added \(=25-18=7\)