Held Prisoner in Hampton Roads

A PhD should be . . .

. . . smarter than a fifth grader. But he wasn't. Missed the first question. Walked away with the grand total of $0.00. Shouldn't a PhD in ANY discipline be able to do third grade math?

The question that was beyond the PhD's math ability:

If a pound of peanuts costs 48 cents, how much does 5/8 of a pound cost?

Now, no cheating, no pencil and paper. Do it in your head. What's the answer?