Posted by Anonymous on .
How many milliliters of pure acid must be added to 150 milliliters of a 70% solution of acid to obtain a 80% solution?

Math 
Reiny,
let the amount to be added be x ml
.7(150) + x = .8(150+x)
times 10
7(150) + 10x = 8(150+x)
solve for x