The ratio of boys to girls in Class A is 3 to 4.

The ratio of boys to girls in Class A is 3 to 4. The ratio of boys to girls in Class B is 4 to 6. If the two classes were combined, the ratio of boys to girls in the combined class would be 17 to 22. If Class A has one more boy and two more girls than class B, how many girls are in Class A?

Quiz

Answer/Solution

11

Steps/Work

Since it is given that the ratio of boys to girls in Class A is 3 to 4 - so we can quickly eliminate the answer choices which are not multiples of 4.
so ans can either be 8 0r 12.
With 8 as answer - no of girls = 8
With 12 as answer - no of girls = 12
Now Class A has one more boy and two more girls than class B and also the ratio of boys to girls in Class B is 4 to 5.
So we are looking for number of girls in B to be divisible by 5.
With 8 as answer -> Girls = 8-2 = 6. (Not possible)
With 12 as answer -> Girls = 12-2 = 5.
So, answer = 11. ( D)