Glen and Eric 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, Glen cycled faster than Eric. He arrived at the finishing point 12 minutes before Eric who was 5 km behind him. Eric 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 Glen's average speed for the remaining 50 km of the trip in km/h?
(a)
60 min = 1 h
12 min =
1260 h =
15 Eric's average speed
= 5 ÷
15 = 25 km/h
Time that Eric took for the trip
= 55 ÷ 25
= 2
525 h
= 2
15 h
= 2 h 12 min
2 h 12 min before 09 30 is 07 18.
(b)
To find the time that Glen took for the remaining 50 km of the trip, we need to use the time that Eric took subtract that of the time taken for first 5 km and the time that Glen was faster than Eric.
Time that Glen took for the remaining 50 km of the trip
= 2
15 -
15 -
15 = 1
45 h
Glen's average speed
= 50 ÷ 1
45 = 27
79 km/h
Answer(s): (a) 07 18; (b) 27
79 km/h