Question

There is a 120 litre mixture of alcohol and water. The ratio of alcohol to water is 7 : 5. A shopkeeper mixes a certain amount of water in order to make the ratio of alcohol to water 5 : 6. Find the new quantity of water is what percentage of original quantity of water in the mixture

Answer 1

according to old ratio i.e 7:5

quantity of alcohol=

120×7/13=70 ltrs.

similarly water's quantity= 50ltrs.

now, in new ratio the quanof alcohol does not change hence 5x=70ltrs

hence x=14

therefore water's quantity=6x =6(14)=84ltrs.

now we want addition of water to the new ratio hence new quantity -old quantity.=84-50=34 ltrs