Question

Answers: A complete answer to the middle paragraph should explain what Jessie's friend did and why it is wrong (by a lot) in plain, common sense, English. This will almost certainly already include an indication of what further information is needed, but if not that should be included as well.

A complete answer to the last paragraph will state the product rule, describe the relation of the derivative to the change, describe how the weekly pay is a product and how the product rule works in this case. An A-level answer will compare this calculus method to the direct calculation