A doctor's prescription

Question

A? doctor's prescription calls for a daily intake containing 5050 mg of vitamin C and 3030 mg of vitamin D. Your pharmacy stocks two compounds that can be? used: one contains 40 %40% vitamin C and 30 %30% vitamin? D, the other 40 %40% vitamin C and 20 %20% vitamin D. How many milligrams of each compound should be mixed to fill the? prescription?

Answer 1

Kaitlyn,

 

Let x and y be milligrams of each compound. Then the total vitamin C and vitamin D should equal 5050 and 3030, respectively. Since you know percentages you can set up total vitamin C to be:

.4x+.4y=5050

The total vitamin D is

.3x+.2y=3030

 

Solve for either x to find y or vice versa and don't forget to check your work!