Question

From a vessel containing only alcohol, six litres are drawn and replaced with water. six litres of the mixture is now taken out and replaced with water. The ratio of alcohol to water now is 9:16. How many litres of alcohol was there initially?​

Answer 1

let the alcohol be x

after replacing it with water

it becomes x-6

x-6/6=9/16

x-6=54/16

x-6=27/8

x=95/8

x=11.8725