The ratio of boys to girls in Class A is 3 to 4. The ratio of boys to girls in Class B is 3 to 5. 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? Answers.
A) 8  B) 9  C) 10  D) 11  E) 12
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 -&gt; Girls = 8-2= 
<gadget id="calculator">8-2</gadget>
<output>6</output>
6. (Not possible)   With 12 as answer -&gt; Girls= 12-2 = 5.   So, answer = 8. ( 8)
<result>A</result>
The ratio of boys to girls in Class A is 3 to 4. The ratio of boys to girls in Class B is 3 to 5. 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?