You mean what you would have paid him if he had worked an hour and a half at his basic rate

Employer: Yes, for the hours he works between 8 and 4, I pay him
a basic rate of $I0 an hour. But if he works an extra hour, suppose
he works until 5 o'clock, then I have to pay him time and a half.
Man: You mean what you would have paid him if he had worked
an hour and a half at his basic rate.
Employer: Right.
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1- What does "what" refer to?

2- Does it mean "amount"?

Thank you