Question

An alloy consists of nickel, zinc, and copper in the ratio 2:7:9. How much of each metal is needed to make 3.6 kg of this alloy?

Answer 1

X(2+7+9)=3.6
x(18)=3.6
x=3.6/18
x=0.2
2*0.2 : 7*0.2 : 9*0.2
0.4 : 1.4 : 1.8

0.4kg of nickel
1.4kg of zinc
1.8kg of copper

Hope this helps :)

Answer 2

Answer

Find out the how much of each metal is needed to make 3.6 kg of this alloy .

To proof

As given

An alloy consists of nickel, zinc, and copper in the ratio 2:7:9 .

This shows that an alloy contains 18 parts and assume one part of alloy be u .

Thus

An alloy consists of nickel = 2u

An alloy consists of zinc = 7u

An alloy consists of copper = 9u

As given

Total weight of alloy = 3.6 kg

Thus equation becomes

2u + 7u + 9u = 3.6

18u = 3.6

$u = \frac{3.6}{18}$

u = 0.2 kg

An alloy consists of nickel = 2 × 0.2

                                           = 0.4 kg

An alloy consists of zinc = 7 × 0.2

                                        = 1.4 kg

An alloy consists of copper = 9 × 0.2

                                             = 1.8 kg

Hence proved