[kroeliewoelie]

On the math part. You have to call 5 dollar in a 15 dollar pot. That is 1:3. So 1/(1+3) = 1/4 = 25% is needed to be good.

Other example:
If you have to call 10 dollar in 15 dollar pot, you are getting 2:3. So you need 2/(2+3) = 40% to break even.

This is the reason minbetting vulnerable hands on dangerous boards is bad. Say your opponent holds AA on a 2 flush board , you hold the nutflush draw, the pot is $2. Villain bets $0,20 into that pot " to extract value". You now have to win the pot 0,2/(0,2+2,2) = 1/12 ~ 8%. Since you will make your flush 33% of times you can profitably draw to the flush.

If villain bets pot, you need 2/(2+2)=50% to break even and a call based on pot odds alone is not justified. Of course other reason for calling may be compelling, such as implied odds and position.