First, we have to assume that you will be sleeping for roughly 8 hours daily. That leaves 4 sets of 4-hour increments... so 4x4=16 hours.

If this medication needs to be taken around the clock, then you will be waking up every 4 hours to take your dose and the days supply will in fact be different.

I'll calculate the days supply for both scenarios.

Back to the first scenario. 2 x 4 = 8 pills per day (or 2 x 6 = 12 pills per day for the around-the-clock dosing).

You have a quantity of 40 pills in the prescription. 40 divided by 5 equals an 8 day supply.

In the second scenario, it would be a 3 day supply (40 divided by 12 = 3 with a remainder).

Patient is prescribed 10g of Glucose. The glucose is presented as a 5% solution in 500ml Saline. How much of the 5% dextrose saline solution do you need