Please help!

1. Penny Dryer recieves a salary of $200 per week plus 6% commission on her sales. Last week she sold $15,900 worth of goods. What was her total salary for the week?

2.Mr. Peterson recieves a 5% commission on the cars he sells. Find the total commission on these sales: $17,325; $18,010; $25,905.

3. Joe Jones recieved a commission of $165 on a $2,750 sale. What was his rate of commission?