Question

How many litres of vinegar should be mixed in a mixture (vinegar + water) of 60 litres in which initial ratio of vinegar to water is 1 : 4 so that the resulting mixture contains 25% of vinegar in it?

Answer 1

(12+x)/60+x = 1/4

48 +4x= 60 + x

3x= 12
x=4

So 4 litres