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

Ratio=7:3
Let,Copper=7xa
Zinc=3x
then,given,
Copper=12.6 gb
From a and b
7x=12.6
x=12.6/7=1.8
So,
zinc =3x=3*1.8=5.4
total weight of alloy=5.4+12.6=18g
Hope it helps you dear

Answer 2

Ratio = 7:3
Copper= 12.6g
Let alloy weight = x
sum of ratio =7+3=10
according to question
7/10of x=12.6
x = 12.6×10/7
x= 126/7
=18
So weight of alloy = 18 gram