Med math question

Ok, so My homework is a bunch of medication math problems. Usually I can watch a YouTube tutorial or find directions on google on how to correctly solve the type of problem I am given. But I'm having the hardest time with this "obstetric medications: magnesium sulfate" topic.
The question is:
"calculate mL/hr (to set IV pump) for 2 grams/hr in 1000 mL IVF"
can can someone please help me solve or explain this problem to me??? I'm so lost 

Jan 5First, you need to know how much magnesium is in the liter of IV fluid. After finding this, why don't you show us what you have done so far to solve this? This will let us see where you're having difficulty, and better help you.

Jan 5So the prompt says "Dose ranged from 1 gram to 4 grams per hour continuous infusion via IV pump. 40 grams added to 1000 mL bag of IVF. Calculate mL/hr IV rate of magnesium sulfate. The total IVF to equal 125 mL/hr" I'm not sure how to even begin to solve this problem. Any help would be greatly appreciated!!

Jan 5If you have 40 g MgSO4 in 1 L, how many mL is 1 g? Once you know this, can you think of a formula that you might be able to use?

Jan 11The formula is:
D/M x V
Apart from this formula, you should memorize/refresh basic conversions (ex. Going from Millilitres to Grams to Litres, etc)... Backwards and forwards and sideways
If you don't get it, PM meLast edit by CaffeinePOQ4HPRN on Jan 11 
Feb 7Hi,
You are starting with 2 g/h and have to change that to mL/h. You will use the ratio of 40 g/1000 mL to do that. The ratios in these problems always equal 1, so they can be flipped upside down if needed.
2 g/h (1000 mL/40 g) = 50 mL/h.
I hope this helps.
Brad Wojcik, PharmD