Question

An alloy contains copper and zinc in the ratio 7:3 . If it contains 12.6 g of copper, how much does this alloy weigh?

Answer 1

hi my friend............
_______

Let the amount of copper= 7x
amount of zinc = 3x
according to the question 
copper= 12.6gram
7x=12.6
=>x=12.6/7=1.8
as x= 1.8
zinc=3x=3*1.8=5.4gram
alloy=12.6/5.4 =12.33...gram

Answer 2

Hello dear ....

Given ratio=7:3
sum of the ratio terms=(7+3)=10
Alloy weighs=7/10 / 126/10
=7/10 × 10/126
=18 g