An MD orders 8mL of cough syrup. It is available in grains 1/6 per 4mL. How many grains does the patient receive?

Question

An MD orders 8mL of syrup. It is available in grains 1/6 per 4mL. How many grains does the patient receive?

Answer 1

Kimberly, this appears to be a proportion, or two equal ratios. it works pretty much like two equal fractions, although our fractions will include fractions within them, but we can do this!

 

Let's let g = the number of grains the patient receives.  We know that (1/6)/4 = g/8. We could flip everything upside down, as long as we keep mL and grains together on the top or bottom.

 

For me, the easiest thing to do is compare the denominators.  Since 8 = 4 x 2, we know that g must be 1/6 x 2, right?

 

1/6 x 2 = 2/6 = 1/3

 

So, the patient receives 1/3 grains.

 

Hope this helps!