## frustrated with proportions math

by Mona

(Portland, OR)

I feel like the answer is right in my face. I know this is a proportion question. But why is my answer coming out either, 20, or 2000?

How many units of heparin are in 50mL of a 100,000 units/L solution?

A. 50 units

B. 500 units

C. 5,000 units

D. 50,000 units

I feel so stupid because this is so easy.