Question

Brass is an alloy made from copper and zinc in the ratio 3:2, based on weight. If 120g of copper are needed for a certain piece of brass, how much zinc will be needed for the same piece?

Answer 1

The answer is 80.
You would first, divide 120 by 3.
Then, multiply 40 by 2.

Answer 2

3 + 2 = 5 Five parts of a whole

3/5 - cooper
2/5 - zinc

3/5 = 120g  [ * (5/3
3/5 *5/3 = 120g * 5/3
1 (100%) = 600/3g = 200g

200g * 2/5 = 400/5g = 80g zinc