I need somewhere to start this problem. Were working on integrals in class and I need help with this Application.

Question: Water flows into an empty storage tank at a rate of V'(t)= 40e^(-0.01t) liters per minute. How much water is in the storage tank after 20 minutes?

What I did to set it up was I setup the integral from 0 to 20 with the integrand being 40e^(-0.01t). Now from here do I just take the anti-derivative and then plug in my times and subract them from eachother?