A sample of 15 litres of Bacardi is found to be adulterated to the extent 10%. How much pure Bacardi should be added to bring up the level of purity to 95%

This one had me a little confused at first also.

But this is how I cracked it:

.10 is impure, so .90(15) is pure Bacardi. ie 13.5 litres.

Let x equal amount of pure Baca to be added.

(13.5 + x)/(15 + x) = 95/100

1425 + 95x = 1350 + 100x

75 = 5x

15 = x

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Pls include reasoning along with all answer posts.

****GMAT Loco****

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