Question

An alloy contains only zinc and copper and they are in the ratio of 7 : 9. If the weight of the alloy is 8 kg, then find the weight of copper in the alloy.

Answer 1

The ratio of the weight of zinc and copper is 7 : 9.

Let the weight of zinc be 7x kg and the weight of copper be 9x kg.

The weight of the alloy = 8 kg

⇒ 7x + 9x = 8

⇒ 16x = 8

⇒ x = `8/16 = 1/2`

So, the weight of copper = `9 xx 1/2` kg = `9/2` kg

= `4 1/2` kg