Carcass wrote:
30 liters of a solution of water and acid contains 15% acid. If more water is added to change the solution to 5% acid, which of the followingrepresents the number of liters of water in the final solution?
A 30
B 57
C 60
D 85.5
E 90
let's break this statement down:
30 liters of a solution of water and acid contains 15% acidIn the phrase aforementioned, the amount of water is
30*0.85If more water is added to change the solutionLet's define the amount of extra water as
XThe amount of water in the final solutionDue to the fact that the final solution
must be five percent acid, the amount of water in that mixture will be 0.95 percent. In addition, that solution has in total 30 liters and x liters. Therefore, the amount of water in the final solution must be:
0.95(30+x)
Finally, setting up the euation, we have:
Water in the initial mixture + additional water = amount of water in the final solution
\(30*0.85 + x = 0.95(30+x)\)
\(x = 60\)
However, 60 stands for the extra water. We need to figure out how much water was previously. The last, can be achieved by multiplying 30*0.85 = 25.5, and adding 60. Therefore, the total amount of water is 60 + 25.5 = 85.5.
Option D.