Hello!
The answer is: $525
Why?
The important fact that we need to consider is that he will earn a 15%of commission only on the sales he makes after his first $1000 in sales, it means that he will earn a 15% for all of his but I will happen only after $1000.
So,
First, we need to convert the 15% into a real number, we can do it by dividing the given % into 100,
Therefore,


So, the gross pay for the week will be $575