2008 AMC 10A Problem 1

A bakery owner turns on his doughnut machine at \text{8:30}\ {\small\text{AM}}. At \text{11:10}\ {\small\text{AM}} the machine has completed one third of the day's job. At what time will the doughnut machine complete the job?

\mathrm{(A)}\ \text{1:50}\ {\small\text{PM}}\qquad\mathrm{(B)}\ \text{3:00}\ {\small\text{PM}}\qquad\mathrm{(C)}\ \text{3:30}\ {\small\text{PM}}\qquad\mathrm{(D)}\ \text{4:30}\ {\small\text{PM}}\qquad\mathrm{(E)}\ \text{5:50}\ {\small\text{PM}}

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.