A pharmacist has 2 hectograms 55 grams of pills. Each pill weighs 1 gram 2 centigrams. How many pills does the pharmacist have altogether?
I came up with B. 250
However, we know that hecto IS a metric prefix, so it must be some multiple of 10. Thus the pharmacist has 2*10^n + 55 grams, where n is some integer. The only number of that form is answer C, 255.