1. John slipped on a marble and nearly fell. "One of yours?" he asked his son, holding up the offending object. "It must be, Dad," replied Harry. "Yesterday I had 45 altogether. Reds, blues and greens. If the blues had been red, I would have had twice as many reds as greens, but if the reds had been green, I'd have had one more green than blues." You work it out!