Problem 22: Race Against the Clocks

All today’s puzzles have something to do with time. Your challenge is answer them as quickly as possible.

BUT if you get any wrong, it is game over. It is more important to get them right than to do them fast!

1. In a lake, a patch of lily pads doubles in size every day. If it takes 48 days to cover the entire lake, how long does it take to cover half the lake?
2. A father is 30 years older than his son. In 10 years, the father will be twice as old as the son. How old is the son now?
3. I have a bunch of machines that make widgets. If 5 machines take 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?
4. You drive 30 miles at 30 mph and then another 30 miles at 60 mph. What is your average speed for the whole trip?