D. You are told that 250 sheets of paper make 1 inch, so to get the height, just divide the amount of ballots by 250 and that is the amount of inches.

20 cuts: 1,048,576 ÷ 250 = 4,194 inches to the nearest inch. (≈117 yards)

30 cuts: 1,073,741,824 ÷ 250 = 4,294,967 inches to the nearest inch. (≈68 miles)

E. A stack of ballots 1 foot high would need 250*12 = 3,000 ballot papers.

The smallest amount of cuts Alejandro would need is 12, because 2^11 = 2,048 and 2^12 = 4,096.