Calculating Total Deposition from a Rate Model

The rate of particulate matter deposition for a remediation project is modeled by the function $R(t) = 20(1 - e^{-0.3t})$, where $R(t)$ is measured in units per day and $t$ is the time in days. Which of the following is the best estimate for the total particulate matter deposited during the first 10 days?