It's 10% I use because it's much easier for calculations. 11.76 is the correct % though but that's a shitty number. People also need to be careful with odds. 7.5/1 means you actually flop the set once every 8.5 hands, twice every 17 hands and not every 7.5 hands. People are far more likely to make mistakes with odds rather than fraction/%. For instance:
Pot odds are your basic odds on calling a bet right now based on the current bet to you and the pot size. For instance, if you facing a bet of 100 into a pot of 300, the pot odds are 3 to 1. If you were against this bet on the river and you felt that you were best at least 34% of the time you should call.
Odds are 4/1 since it's your 100 to win 400 + your stake. It's like placing a £100 bet and getting £500 back if you win. You actually only need 20% winrate to make it 0EV since if you played a 4/1 bet 5 times and won once you would lose 4 x £100 on the bad bets and return £500 on the good bet, £100 of which was already yours. So if we are in this spot with 100 to call and run that 5 times, 4 of which we lose and 1 of which we win, our net gain/loss is 0. The important thing to remember is that the money we have already put into the pot is no longer ours, it belongs to the pot. So the 100 the guy has bet no longer belongs to him, the pot is 400 and 100 for us to call.
So if the odds are 3/1 you only need 25%, not 33.3%
So implied odds again. The chance of you flopping your set are "one in 8.5" (7.5/1) ~ 10%. Let's says it's 1 out of 9. This means that 8 of the 9 hands you lose whatever you call (perhaps). The other 1 times you need to make this back up to make the play profitable at least. This is why you can call 10% of the effective stack preflop with a pocket pair since more or less you lose this 90% of the time and lose 90% of your stack worth of chips but the other 10% of the time you are hoping to pretty much stack them. You don't get good implied offs in situations with flushes so much because when you actually hit it's much harder to get pair.
An example where implied odds are useful is a board of AK92 with two of a suit when you have been up against significant aggression preflop. You know they are strong like AK or something and have 45s with the flush draw. The odds for making a call might not be good enoguh since they might be a lot but you have implied odds since if you catch the 3 or card of your suit you feel you might be able to stack them, specially with the 3.
I really wouldn't worry about this too much now though mortal. We will work on more important lessons later.
Well done satriales, play cash and take over the world!