Mr$.$ and Mrs$.$ Smith are running short of money this month and they have decided to borrow $$500$ from the bank and repay the money in $6$ months when they get their income tax refund check. The bank charges $6\%$ annual simple interest.

$(10$ points each$)$

$($A$)$ How much interest will they owe at the end of the six months?

$($B$)$ How much will they have to pay to the bank at the end of the $6$ months?