Question

Let the ratio of water and milk be 1:4 in a filled can of capacity 100 litres. the mixture was added with more water so as to change the ratio of 3:8. find the quantity of water present originally and the amount of water (in litres) added thereafter.

Answer 1

The sum of the ratios is :

1 + 4 = 5

The amount of water in the mixture is :

1/5 × 100 = 20 lites

Amount of milk is :

100 - 20 = 80litres

Let the added amount of water be x then the new volume is :

20 + x

The new ratio is :

20 + x : 80 = 3 : 8

20 + x / 80 = 3/8

8(x + 20) = 3 × 80

8x + 160 = 240

8x = 240 - 160

8x = 80

x = 80/8

x = 10 litres

The amount added is thus 10 litres