Spoon, aside from the exercise, I hate to contradict you but:
- if we bet 5 into a 7.5 pot, the pot becomes 12.5
- if villain called, the pot would be 17.5. That is the amount he needs to raiseon top of his call to make a pot sized raise
- so a pot sized raise would be a raise to (17.5 + 5) = 22.5, not to 17.5.