Question

The ratio of milk and water is 7:2 in 72.9 litre of a mixture. Find the separate quality of milk and water.

Answer 1

Answer:

Ratio of milk to water in a mixture of milk and water of 72.90 litres is 7:2.

Add x litres of water to make the ratio 7:3.

Initially there were 7x litres of milk and 2x litres, or

7x+2x = 72.90, or

9x = 72.9, or

x = 8.1

So the milk was 56.7 litres to 16.2 litres water.

Now add w liters of water to the mixture to get

56.7 litres (milk) and (16.2 +w) litres of water.

Now 56.7 : (16.2+w) = 7:3 or

3*56.7 = 170.1 = 7×16.2 + 7w, or

7w = 170.2–113.4 = 56.8, or

w = 56.8/7 = 8.11 litres.

So add 8.11 litres to the original to get the new milk to water ratio as 7:3.