Question

A sample of 5 litres of mixture of paint and thinner is formed to have 20% thinner. find how much pure paint should be added to bring down the percentage of thinner to 10%.

Answer 1

more 10 percent needs to be added

Answer 2

Total quantity of solution= 5ltrs

quantity of thinner in it = 20%

So remaining quantity= 100 - 20% = 80%

ratio = 20:80 = 2:8 = 1:4

pure paint should be added to bring down the percentage of thinner to 10%.

so the new ratio will be

90 : 10 = 9:1

in the initial solution.. Paint = 5 and now its 9

so we have to add 9-5 = 4 parts to make it 10% thinner

i.e., 5×80% = 4ltrs