280 is 72% of what number?

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?

Which ordered pair (c, d) is a solution to the given system of linear equations- c+2d=13 -9c-4d=-15

Match each function with its rate of growth or decay