Simple problem this time, with only one solution...
Imagine a pie. A hot, sloppy, scrumptious blueberry pie, fresh from the oven. And you have the perfect knife to cut it with, sliding into the crust with zero breakage and clean lines.
Now, you know that cutting a single vertical slice into this pie will result in 2 pieces. A second vertical slice can yield 4 pieces, and a third vertical slice, properly placed, can create as many as 7 pieces.
The discount code for this puzzle is the maximum number of pieces created by 10 vertical slices in the pie.
Piece of cake, right?