Shirley completed 36 x 2 = <<36*2=72>>72 questions
The sum of Fiona and Shirley's questions is 36 + 72 = <<36+72=108>>108
Kiana completed 108/2 = <<108/2=54>>54 questions
In one hour, they completed 108 +54 = <<108+54=162>>162 questions.
In two hours, they completed 162 x 2 = <<162*2=324>>324 questions.
#### 324