akshayk wrote:
A factory cleans its machinery with a solution that is 87% water and the remainder vinegar. If the factory manager starts with 260 Litres of a 40% vinegar solution, how much water must the manager add to the existing solution to attain the proper vinegar concentration for cleaning the machinery?
A) 104 Litres
B) 120 Litres
C) 470 Litres
D) 540 Litres
E) 800 Litres
We have a solution that is 40% vinegar. We need to add water, which is 0% vinegar, to obtain a resultant solution that is 13% vinegar.
Let A = solution with 40% vinegar
Let w = amount of water to be added
A + w = Total volume of resultant mixture
Water is 0% vinegar.
(Concen. of A)(Vol of A) + (Concen. of w)(Vol of w) = (Desired concen. of resultant solution)(Vol of resultant solution)
.40(A) + (0)w = .13(A + w)
.40(240) + 0w = .13(240 + w)
104 + (0)w = (.13)(240) + .13w
104 = 33.8 + .13w
70.2 = .13w
7020 = 13W
w = 540
Answer D
_________________
Listen, are you breathing just a little, and calling it a life?
-- Mary Oliver
For practice SC questions with official explanations that were posted and moderated by the SC Team,
go to SC Butler here: https://gmatclub.com/forum/project-sc-butler-get-2-sc-questions-everyday-281043.html