DAY 17
How many one-inch cuts would it take to cut a 30-inch ribbon into 30 pieces?

Answer:

29---The 30th piece falls off after the 29th cut.

DAY 18
A logger has two identical logs. He cuts one log into four pieces in 36 seconds. How long will it take to cut the other log into five pieces?

Answer:

48 seconds---To cut the first log into four pieces requires only three cuts. So each cut takes 12 seconds. (Refer to Day 17 example.)