Question

The ratio of mass of zinc and copper in an alloy is 5 : 9. If the mass of alloy is 11.2 kg, find
the mass of zinc in it.

Answer 1

Let the mass be x

5x+9x=11.2

14x=11.2

X=11.2/14

x=0.8

Zinc: 5x=5 x 0.8=4

Answer 2

ratio=5:9

total mass=11.2kg

part of zinc in alloy=5/14

mass of zinc=5/14x11.2

=5x0.8

=4kg