# Thread: Alligation problem?

1. ## Alligation problem?

Q) A vessel contains 70 lts of liquid which have 10% of water.How much water is added to the mixture so that the final mixture contains 12.5% of water?

Any help would be greatly apppreciated?

Thanks,
Ashish

2. "Alligation"? Is that what Alligators do?

"A vessel contains 70 lts of liquid which have 10% of water." Okay, 10% of 70 is 7 so we have 7 l of water in 70 l overall.

"How much water is added to the mixture so that the final mixture contains 12.5% of water?"
Let x be the amount of water added, in liters. Then we have x+ 7 liters of water, in x+ 70 liters overall. The concentration is now $\frac{x+ 7}{x+ 70}= 0.125$. Solve that for x.