Randolph Is Taking Three Courses This Semester: Economics, Statistics, and Finance

Randolph is taking three courses this semester: economics, statistics, and finance. He has decided to spend 20 hours per week studying (in addition to attending all his classes) and his objective is to maximize his average grade, which means maximizing the total of his grades in the three courses. The table shows Randolph's estimate of the relation between time spend studying and his grade for each course.

$\begin{array}{cccc}&&\text{grade in}\\\text { Hour's of stuay } & \text { Economics } & \text { Statistics } & \text { Finance } \\\hline 4 & 63 & 54 & 68 \\5 & 72 & 64 & 76 \\6 & 79 & 72 & 82 \\7 & 85 & 78 & 87 \\8 & 88 & 83 & 90 \\9 & 90 & 87 & 93 \\10 & 92 & 89 & 95\end{array}$
-How should Randolph allocate his time?

A) 7 hours economics, 7 hours statistics, 6 hours finance
B) 6 hours economics, 6 hours statistics, 8 hours finance
C) 7 hours economics, 6 hours statistics, 5 hours finance
D) 6 hours economics, 5 hours statistics, 7 hours finance
E) none of the above