Of the 120 passengers on Flight 750, 50% are female. 10% of the passen

We can also solve this question by using a technique called the Double Matrix Method.
This technique can be used for most questions featuring a population in which each member has two characteristics associated with it (aka overlapping sets questions)..
Here, we have a population of passengers, and the two characteristics are:
- male or female
- first class or coach class

Of the 120 passengers on Flight 750, 50% are female. 10% of the passengers sit in first class, and the rest of the passengers sit in coach class.
With this information we can set up our diagram as follows:


1/3 of the passengers in first class are male
We already know that there are 12 passengers in first class
1/3 of 12 = 4, so there are 4 male passengers in first class
So we get:


At this point we can fill in the remaining boxes to get:


How many females are there in coach class?
The yellow box above denotes the number of females in coach class
So we can see that there are 52 females in coach class

Answer: D

This question type is VERY COMMON on the GMAT, so be sure to master the technique.

To learn more about the Double Matrix Method, watch this video: