Can someone help me get my push-ups higher, i want to be an Army Ranger, but i need to get my max push ups up?

i can do around 40, in like 30 seconds(legit ones) but i just get way way to soar to do anymore. (hands are also shoulder width apart) i read on the cpu that you have to do 59? if that's so can somebody help me up that. like what program should i go on. i can do the cardio im sure, and i can do the sit ups no joke, the only thing is the push ups. o ya im 15 so i have 2 years til i sign up for dep.