a mixture that contains 12% of a medication to treat an injured bird. How many milliliters of a 16% solution should be mixed with 4 mL of a 4% solution to obtain a solution that is 12% medication?

Answer 1

.16x + .04(4) = .12(x+4)

.16x - .12x = .12(4) - .04(4)

.04x = .08(4)

x = .08(4)/.04

x = 2(4)

x = 8 mL of 16% solution mixed with 4 mL of 4% yields 12 mL of 12% medication

16 is within 4 of 12

4 is within 8 of 12

you need 8/4 = 2 = twice as much of 16% as of 4%

8mL/4mL = 2