Idon't get #3! the one where my finger is pointing is what i'm asking for.

Okay so lets break down the problem. We have 25 players total. 13 play only offense, 13 play defense, and 5 play both. The way I would solve this is by saying 13+13+5 = 31. Then I would take the total amount of players and subtract it by the total amount of players on the Steelers. This question doesn't make sense because it says there are only 25 players. It sounds like there was a typo and they meant 35 instead of 25?

I hope this helps !!