Question

A patient receives 3.0 mL of a solution containing technetium-99m for a breast image. If the activity of the technetium-99m is 9.5mCi/mL what is the dose received by the patient?
Answer Choices are:
a)29mCi b)3.2mCi c)320uCi d)28.5mCi

So I times 3.0mL * 9.5 = 28.5
But the answer in the book is 29mCi
So why would it be 29mCi and not 28.5?
Thanks for your help!

Answer 1

I, too, obtained 28.5 mCi; however, that isn't the problem. The problem is that the number 3.0 mL has only two significant figures as does the 9.5; therefore, you can't have an answer with 3 s.f. I would round the 28.5 to 28 but that isn't one of the choices so 29 is the obvious one to choose.