if an alloy containing 30% silver is mixed with a 55% silver alloy to get 800 pounds of a 40% alloy, How much of each is used?

What is the exact area of a circle with a diameter of 50 centimeters? a.87.9 square centimeters b.379.9 square centimeters c.1962.5 square centimeters d.4923.5 square centimeters

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?