Julian and Wesley started on a 45-km cycling trip at the same time. They cycled at the same speed for first 10 km. For the remaining 35 km, Julian cycled faster than Wesley. He arrived at the finishing point 30 minutes before Wesley who was 10 km behind him. Wesley 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 Julian's average speed for the remaining 35 km of the trip in km/h?
(a)
60 min = 1 h
30 min =
3060 h =
12 Wesley's average speed
= 10 ÷
12 = 20 km/h
Time that Wesley took for the trip
= 45 ÷ 20
= 2
520 h
= 2
14 h
= 2 h 15 min
2 h 15 min before 08 30 is 06 15.
(b)
To find the time that Julian took for the remaining 35 km of the trip, we need to use the time that Wesley took subtract that of the time taken for first 10 km and the time that Julian was faster than Wesley.
Time that Julian took for the remaining 35 km of the trip
= 2
14 -
12 -
12 = 1
14 h
Julian's average speed
= 35 ÷ 1
14 = 28 km/h
Answer(s): (a) 06 15; (b) 28 km/h