Bryan and Warren started on a 35-km cycling trip at the same time. They cycled at the same speed for first 5 km. For the remaining 30 km, Bryan cycled faster than Warren. He arrived at the finishing point 20 minutes before Warren who was 5 km behind him. Warren did not change his speed throughout and completed it at 09 30.
- At what time did the trip begin? Give the answer in 12-hour format.
- What was Bryan's average speed for the remaining 30 km of the trip in km/h?
(a)
60 min = 1 h
20 min =
2060 h =
13 Warren's average speed
= 5 ÷
13 = 15 km/h
Time that Warren took for the trip
= 35 ÷ 15
= 2
515 h
= 2
13 h
= 2 h 20 min
2 h 20 min before 09 30 is 07 10.
(b)
To find the time that Bryan took for the remaining 30 km of the trip, we need to use the time that Warren took subtract that of the time taken for first 5 km and the time that Bryan was faster than Warren.
Time that Bryan took for the remaining 30 km of the trip
= 2
13 -
13 -
13 = 1
23 h
Bryan's average speed
= 30 ÷ 1
23 = 18 km/h
Answer(s): (a) 07 10; (b) 18 km/h