Solve the problem.
-In a chemistry class, 7 liters of a 4% silver iodide solution must be mixed with a 10% solution to get a 6% solution. How many liters of the 10% solution are needed?
A) 3.5 L
B)7 L
C) 4.5 L
D) 2.5 L

Question

Quizplus · Accepted Answer

Let x be the number of liters of the 10% solution needed.4% of 7 liters = 0.28 liters of silver iodide10% of x liters = 0.1x liters of silver iodideIn the final solution, 6% of (7 + x) liters = 0.06(7 + x) liters of silver iodideSince the amount of silver iodide is the same in all solutions, we can set up the equation:0.28 + 0.1x = 0.06(7 + x)0.28 + 0.1x = 0.42 + 0.06x0.04x = 0.14x = 3.5Therefore, 3.5 liters of the 10% solution are needed.

Solve the Problem. -In a Chemistry Class, 7 Liters of a 4% Silver