a lab technician needs to mix a 45% phosphorus solution with an 18% phosphorus solution to obtain 12 militiers of 36% phosphorus solution how many millitiers of the 18%

Question

a lab technician needs to mix a 45% phosphorus solution with an 18% phosphorus solution to obtain 12 militiers of 36% phosphorus solution how many milliliters of the 18% phosphorus solution will the lab technician need

Answer 1

.45x + .18(12-x) = .36(12)

.45-.18x = .36(12)-.18(12)

.27x = .18(12)

x = .18(12)/.27 = 2(12)/3 = 8 ml of 45% mixed with 4 ml of 18% yields 12 ml of 36%

check the answers

45-36 = 9

36-18 = 18

18/9 = 2

twice as much 45% is needed as 18% to get 36%

8ml/4ml = 2

.45(8)+ .18(4) = 3.6 +.72 = 4.32

.36(12) = 4.32