A group of college students is volunteering for Homes for the Community during their spring break. They are putting the finishing touches on a house they built.
 Working alone, Wade can paint a certain room in 7 hours. Rhonda can paint the same room in 5 hours. How long will it take them working together to paint the
 room? Round your answer to the nearest hundredth, if necessary.
 A. 17.5 hours
 B. 0.08 hours
 C. 6 hours
 D. 2.92 hours