PLZ HURRY!!!! 15 POINTS!
Mary is babysitting a 4-year-old. The little boy wants to play in the kiddie pool in the backyard. Mary knows that using the hose that is near the kiddie pool will take 30 minutes to fill up. The little boy has already asked 17 times if the pool is ready but she hasn't even turned on the water yet. Mary also knows that the hose from the front yard works faster and can fill the pool in 1/2 the time as the hose in the back yard. If she can use both hoses at the same time, how long will it take for the pool to fill up?