How do I do this?? TnT

Rita wants to buy sweater that was originally priced at $25 today the sweater is on sale for 40% off the original price what is the sale price of the sweater. rita has a coupon for an addition 10% off the sale price. how much will rita pay for the sweater before taxes

Amerchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. how many pounds of the & 60 coffee should be used?

Apackage of five erasers cost 0. $.39 at this rate how many how much would 60 erasers cost in dollars and cents