Sorry for all the posts lol (Math Question)

[Guest guest]

I was taking a practice test and noticed quite a few questions like this:

" How many milligrams of atropine sulfate are needed to make 30ml of a 1:200

solution "

The question is simple enough but I can't, for the life of me, remember how to

solve it! Does anyone know a simple, easy to remember, process of how to solve

it?

Another, similar one, went like this

" What is the percentage strength of a 1:1,500 solution?

I feel so silly for not remembering simple ratio! The way the book explained it

all just left me going " huh? "