The first thing you have to do is to know what its taking about.
So We know that Ben played with his friends for 2 hours and 35 min's.
Then he played somewhere at a park for like 3 hours and 52 mins.
Second thing Is that we know know what the question is talking about so the next step is easy all we have to do is subtract the time he was at his friends house and the time he was at the park. So the question is asking us How long did Ben play at the park?
Your best answer is 1 hour and 17 mins (1:17)