Valen and Ben 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, Valen cycled faster than Ben. He arrived at the finishing point 12 minutes before Ben who was 5 km behind him. Ben did not change his speed throughout and completed it at 07 25.
- At what time did the trip begin? Give the answer in 12-hour format.
- What was Valen's average speed for the remaining 50 km of the trip in km/h?
(a)
60 min = 1 h
12 min =
1260 h =
15 Ben's average speed
= 5 ÷
15 = 25 km/h
Time that Ben took for the trip
= 55 ÷ 25
= 2
525 h
= 2
15 h
= 2 h 12 min
2 h 12 min before 07 25 is 05 13.
(b)
To find the time that Valen took for the remaining 50 km of the trip, we need to use the time that Ben took subtract that of the time taken for first 5 km and the time that Valen was faster than Ben.
Time that Valen took for the remaining 50 km of the trip
= 2
15 -
15 -
15 = 1
45 h
Valen's average speed
= 50 ÷ 1
45 = 27
79 km/h
Answer(s): (a) 05 13; (b) 27
79 km/h