Question

As a nurse, part of your daily duties is to mix medications in the proper proportions for your patients. For one of your regular patients, you always mix Medication A with Medication B in the same proportion. Last week, your patient's doctor indicated that you should mix 120 milligrams of Medication A with 156 milligrams of Medication B. However this week, the doctor said to only use 78 milligrams of Medication B. How many milligrams of Medication A should be mixed this week?

Answer 1

To determine the number of milligrams for Medication A, use the following proportion:

`(120)/(156)=(x)/(78)`

where the numerators are the milligrams for Medication A and the denominators are the milligrams for medication B.

To solve for x, which is the weight of Medication A, multiply both sides of the equation by 78 and then simplify.

`\begin{gathered} 78\mleft((120)/(156)\mright)=x \\ (120)/(2)=x \\ 60=x \end{gathered}`

Note that we multiplied 78 to 1/156 which resulted to 1/2. Then, we divided 120 by 2.

Therefore, there must be 60 milligrams of Medication A in order to maintain the previous ratio.