Question

Brass is an alloy formed using 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 is needed?

PLEASE HELP!!

Answer 1

80g of Zinc will be needed with 120g of Copper

Explanation:

Answer 2

Hey There :)

We can solve by 2 ways ( The 2nd way might be easier )

→ To make 1 brass alloy, the ratio of copper to zinc is 3 : 2
Brass = copper + zinc
= 3 : 2
3x : 2x

Copper needed is 120g
↓
3x = 120g
Divide by 3 to isolate x

`(3x)/(3) = (120)/(3)`
x = 40

Ratio of Zinc is 2

substitute 40 in place of x
2x = 2 ( 40 ) = 80g

Or

→ 3 : 2
120 : p

Cross multiply
3p = 120 x 2
3p = 240

`(3p)/(3) = (240)/(3)`
p = 80g

80g of Zinc will be needed with 120g of Copper