A pharmacist wants to mix a 45% saline solution with a 27% saline solution to get 108 mL of a 40% saline solution. How much of each solution should she use? Round your answer to the nearest mL.

Answer 1

X + Y = 108

0.45X + 0.27Y = 108*0.4 = 43.2

0.45 x + 0.27 ( 108-x) = 43.2

0.45x + 29.16 - 0.27x = 43.2

0.18x = 43.2 - 29.16

0.18x = 14.04

x = 78

then y = 30

Finally,

78 * 0.45 + 30*0.27 =

35.1 + 8.1 =

43.2

Official answer:

78 mL of the 45% saline solution

and 30 ml of the 27% saline solution