Simon and John started on a 48-km cycling trip at the same time. They cycled at the same speed for first 5 km. For the remaining 43 km, Simon cycled faster than John. He arrived at the finishing point 20 minutes before John who was 5 km behind him. John did not change his speed throughout and completed it at 07 30.
- At what time did the trip begin? Give the answer in 12-hour format.
- What was Simon's average speed for the remaining 43 km of the trip in km/h?
(a)
60 min = 1 h
20 min =
2060 h =
13 John's average speed
= 5 ÷
13 = 15 km/h
Time that John took for the trip
= 48 ÷ 15
= 3
315 h
= 3
15 h
= 3 h 12 min
3 h 12 min before 07 30 is 04 18.
(b)
To find the time that Simon took for the remaining 43 km of the trip, we need to use the time that John took subtract that of the time taken for first 5 km and the time that Simon was faster than John.
Time that Simon took for the remaining 43 km of the trip
= 3
15 -
13 -
13 = 2
815 h
Simon's average speed
= 43 ÷ 2
815 = 16
3738 km/h
Answer(s): (a) 04 18; (b) 16
3738 km/h