Question

a certain mixture contains copper and tin. if 20% of the mixture is removed and replaced with tin, the ratio of copper and tin becomes 16:9. what was the ratio of copper and tin in initial mixture

Answer 1

# Answer copper:tin = 4:1

# Explaination-

Consider an initial mixture with

copper = x quantity

tin = y quantity

Removing 20% of the mixture ratio of copper to tin = 80%x : 80%y

Adding tin to 20% of initial mixture, ratio becomes

80%x:80%y+20%(x+y)

This ratio is given 16:9

Hence,

80%x / 80%y+20%(x+y) = 16/9

72x = 128y + 32x + 32y

5x = 20y

x:y = 4:1

Initial ratio of mixture will be copper:tin = 4:1