in a chemistry class 14 liters of a 12% alcohol solution must be mixed with a 20% solution to geta 13% solution how many liters of the 20% solution are needed? .....please help, not sure how to set up
Let the number of Liters of 20% solution = T
12%*14 + 20%*T = 13%[14 + T]
1.68 + 0.20T = 1.82 + 0.13T subtract 0.13T from both sides
1.68 + 0.07T = 1.82 subtract 1.68 from both sides
0.07T = 0.14 divide both sides by 0.07
T = 2 - Liters of 20% solution will be needed to make 13% solution.