ok here is the question..

how many quarts of alcohol must be added to 10 quarts of a 25% alcohol solution to produce 40% alcohol solution?

i dunno i jus feel like i have too many unknowns..

i tried to use barrels to make sense of the problem..

in the first barrel i have 10 gallons of 25% solution + X gallons of Y% which will yield (10 +X) gallons of 40% solution?

ok where did i go wrong with this problem, because its not working out.

thanks in advance