It really depends on how good you did in a match, how many matches you play, if you win etc. The easiest way to make it look like your leveling up faster is pick a champion that you play good and just do a lot of good matches because even if you are gonna win or lose if you had 17/2/7 you hsould still get some exp. Now from my experience if you look everytime at what lvl you are and dont really enjoy the game it is gonna take a while. Also why are you hurring to 30? You will get to ranked where you will have 14/1/7 and your'top or mid will be saying that you are trash when he has 5/12/1