Fiona completed 36 math questions in an hour. Shirley was able to complete twice as many math questions within that same time, and Kiana completed half of the sum of Fiona and Shirley's math questions. If they each did the same number of questions the following hour, how many math questions did all three girls complete in 2 hours?
Thoughts? Step-by-step reasoning:
Shirley completed 36 x 2 = 72 questions. The sum of Fiona and Shirley's questions is 36 + 72 = 108. Kiana completed 108 / 2 = 54 questions. In one hour, they completed 108 + 54 = 162 questions. In two hours, they completed 162 x 2 = 324 questions.
Thus, the answer is 324.