3. Carl leaves home on his bicycle at 9:30am. His sister, Karen, who can ride 3 mph faster than Carl, leaves home at 10:30am to catch up with him. If they use the same route and Karen rides 10 hours before catching Carl, what is Karen's rate? 4. Sue drove at a steady speed for two hours. She then ran into heavy traffic which reduced her speed by 25 mph for the rest of the trip. What was her average speed on the first part of the trip if the whole 125 mile drive took her 3 hours? SAY 5. Tom runs 10 meters per second and Al runs 6 meters per second. If Al has a 50 meter head start, how long will it take Tom to catch Al? G 6. A commuter takes an hour to get to work. Part of the trip is on the Metra train averaging 65 mph, and the rest is on a bus averaging 25 mph. How long she rides on the bus if the entire distance travelled to work is 55 miles?