Tom and Ian started on a 55-km cycling trip at the same time. They cycled at the same speed for first 5 km. For the remaining 50 km, Tom cycled faster than Ian. He arrived at the finishing point 12 minutes before Ian who was 5 km behind him. Ian did not change his speed throughout and completed it at 08 30.
- At what time did the trip begin? Give the answer in 12-hour format.
- What was Tom's average speed for the remaining 50 km of the trip in km/h?
(a)
60 min = 1 h
12 min =
1260 h =
15 Ian's average speed
= 5 ÷
15 = 25 km/h
Time that Ian took for the trip
= 55 ÷ 25
= 2
525 h
= 2
15 h
= 2 h 12 min
2 h 12 min before 08 30 is 06 18.
(b)
To find the time that Tom took for the remaining 50 km of the trip, we need to use the time that Ian took subtract that of the time taken for first 5 km and the time that Tom was faster than Ian.
Time that Tom took for the remaining 50 km of the trip
= 2
15 -
15 -
15 = 1
45 h
Tom's average speed
= 50 ÷ 1
45 = 27
79 km/h
Answer(s): (a) 06 18; (b) 27
79 km/h