It takes Bob five minutes to saw a board into three pieces. How long would it take him to saw a board into nine pieces? HINT: The answer is NOT fifteen minutes.
1 answer
it takes 5 minutes to make 2 cuts to give you 3 pieces. so if you continue at a rate of two cuts per 5 minute and in order to get 9 pieces you need 8 cuts. so I think 20 minutes