About 94 sheets if 4x8.
Between the sheets of drywall can be insulation or just hollow.
You will need at least 14 sheets, depending on shape and height of wall.
4' x 12' = 48 sq ft
You need roughly 94 sheets, however, the shapes of walls and stairs will change that figure slightly.
3.5 sheets to cover that.
Each sheet covers 48 square feet. Divide 1500 by 48 gives you 31.25 sheets of drywall.
Impossible to say without knowing how many rooms and what size they are.
Oh, dude, you're really concerned about drywall quantities, huh? Well, typically, there are about 500 sheets of drywall in a pallet. But hey, who's counting, right? Just make sure you have enough to cover those walls, or don't, like, whatever floats your boat.
Depending on doors and windows that is approximately 500 sq.ft or 16 standard boards.
That will take 27 sheets.
A 'lift' (100 ) of standard drywall sheets weighs about 2.5 tons on a dry day, -so you figure it out according to size of your truck.