Math
posted by Heather .
If a nickel contains 3.9 gram of copper and 1.2 gram of nickel How many kilograms of copper must be combines with 500 kilograms of nickel to make nickel coins?

(3.9/1.2) x 500 = ____ kg
The ratio of copper mass to nickel mass remains the same for this coin.
The present nickel, like the cent and other coins, are "sandwiches". The outer surfaces contain more nickel than the inside; otherwise the coin would look bronze (like the Sacajawea dollar).