Two people are mowing a large lawn. One person has a riding lawnmower, and the other person has a push mower. The person with the riding mower can cut the lawn alone in 3 hours, and the person with the push mower can cut the lawn alone in 6 hours. How long does it take for them, working together, to cut the lawn? (Fractional answers are OK.) The riding mower cutting rate is per hour. The push mower cutting rate is per hour. The combined cutting rate is per hour. It will take them hour(s) to cut the lawn together.