On your cousin's wedding day you leave for the church 30.0 min before the ceremony is to begin, which should leave plenty of time since the church is only 17.0 km away. On the way, however, you have to make an unanticipated stop because of road construction work. As a result your average speed for the first 15 min is only 11.0 km/h. What average speed do you need to have on the remainder of the trip to get you to the church on time? Express your answer to three significant figures and include the appropriate units.