The kid's not stupid, he just didn't know how to interpret the question. It's not his fault he doesn't intuitively know what typical LED currents are.
No, he's not stupid, and I agree he probably didn't know how to interpret the question. But he also refused to participate in finding the answer. I gave him the equation, all he had to do was plug in the numbers and get a result.
Then, once he knows how much current is flowing in each case, it's time to ask how much current is typical for an LED. But he stood still, refusing to take one step just because he knows he'll need help again before the second step.