Chapter 5.2, Problem 83E

Oil production. Using production and geological data, the management of an oil company estimates that oil will be pumped from a field producing at a rate given by

     $\begin{array}{cc}R\left(t\right)=\frac{100}{t+1}+5& 0\le t\le 20\end{array}$

where R(t) is the rate of production (in thousands of barrels per year) t years after pumping begins. How many barrels of oil Q(t) will the field produce in the first t years if Q(0) = 0? How many barrels will be produced in the first 9 years?