Oil leaks out of a tanker at a rate of $r=f(t)$ liters per minute, where $t$ is in minutes. If $f(t) = A e^{-k t}$, write a definite integral expressing the total quantity of oil which leaks out of the tanker in the first hour.

total quantity = $\displaystyle \int_{a}^{b}$ , where $a =$ and $b =$ .

What are the units of this integral? units