Wasim is paid on a graduated scale of 5% on the first $10,000 of sales in a month, 7% on the next $25,000, and 9% on all additional sales.

a)What will he be paid in a month in which sales are $62,760? (round the answer to the nearest cent.)

b)What fixed commission rate would result in the same earnings for the month? (final answer in percentage form and are accurate to 2 decimal places.)

a.

10,000 * 0.05 = ?
25,000 * 0.07 = ?
27,760 * 0.09 = ?

Add those products.

b.
How do you think you should solve this one?