Help please. Hw question in pic

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?

James was playing a game with his friends. he won 35 points. then he lost 15, lost 40 and won 55. how did he come out

2.5 milligrams is equivalent to how many grams