I need to take a physical test for admission in the service academy.

Maximum scores I am concerned with are:

Push-ups: 60 (At a 2 second cadence for 2 minutes)

Sit-ups: 100+ in 2 minutes

Currently I can do about 25 push-ups and 40ish sit-ups(before my back hurts or my abs give out)

I am pretty skinny... 6'4" and about 166lbs. so I'm trying to put as much muscle before my test in mid January.

I am aiming for the maximum scores so that I can challenge myself. How much progress can I expect?

Can anyone recommend an exercise regimen?

Thank you!

Please don't say I can't do this or some "you're not meant to be" crap. I am serious about putting effort into this.