no i mean if you play 3 games of 20 min or one of 60 then the exp should be kinda the same. i think but im not sure go to league of legends wiki and search exp theyll explain it i guess :) im just trying to help but not sure
The amount of experience received for a game is determined by several rules:
Wins are worth more XP than losses.
Longer games are worth more XP.
Wins on PVP Summoner's Rift give approximately 5.767 base XP plus 6.626 XP per minute of game length.
The minimum time any game needs to last to be eligible for XP rewards is 7 minutes.
---> better to win 3 games 20min then 60min cuz the base exp (if i interpret this right haha)