Suppose that a nurse needs 20 cc (cubic centimeters) of a 15.5% solution (that is, a solution that is 15.5% ingredient) of a certain medication, which must be obtained by mixing cc of a 20% solution and cc of a 5% solution. Choose the expression for in terms of .

Question

Suppose that a nurse needs 20 cc (cubic centimeters) of a 15.5% solution (that is, a solution that is 15.5% ingredient) of a certain medication, which must be obtained by mixing  cc of a 20% solution and  cc of a 5% solution. Choose the expression for  in terms of  .

Quizplus · Accepted Answer

Let x be the amount (in cc) of the 15.5% solution needed. Then we have the following equation:

0.20(11-x) + 0.05x = 0.155(11)

Simplifying and solving for x, we get:

0.20(11-x) + 0.05x = 1.705
2.2 - 0.2x + 0.05x = 1.705
-0.15x = -0.495
x = 3.3

Therefore, the nurse needs to mix 11 - 3.3 = 7.7 cc of the 20% solution with 3.3 cc of the 5% solution to obtain 20 cc of the 15.5% solution. Thus, the expression for 11eb0d3b_9770_dde5_9790_e5dfd31c5255_TB1243_11 in terms of 11eb0d3b_9770_dde6_9790_a16f3c287631_TB1243_11 is 7.7, which corresponds to choice B.

Suppose That a Nurse Needs 20 Cc (Cubic Centimeters) of a 15.5