Im doing a small project for a college class.. im leading a team of a few people to build a really simple small gravel driveway. The dimensions will be 15' x 15'. We'll first lay a thin layer of scalping stone, vibrate it and then throw on some gravel (after we edge the square . Im guessing we should have a good 3" layer and it will take between 4 and 5 yards which well be having delivered and dumped right on the spot. Could anyone give me a rough time estimate for how long this should take?Thanks a lot in advance!