Especially at higher reps, these are *plenty* to get your heart rate up, so you get in your cardio. High-rep pushups sets are essentially a plank position held fr >30s, so you get some core. Pushups & squats hit nearly as many muscles as possible for the time spent, so this will also give you a good base if you decide to hit up a gym at some point.
lim x--> inf of x/x is "infinity/infinity" and evaluates to 1.
lim x--> inf of e^x/x is also "infinity/infinity" but evaluates to infinity.