Albert and Tim 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, Albert cycled faster than Tim. He arrived at the finishing point 20 minutes before Tim who was 5 km behind him. Tim 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 Albert's average speed for the remaining 30 km of the trip in km/h?
(a)
60 min = 1 h
20 min =
2060 h =
13 Tim's average speed
= 5 ÷
13 = 15 km/h
Time that Tim 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 Albert took for the remaining 30 km of the trip, we need to use the time that Tim took subtract that of the time taken for first 5 km and the time that Albert was faster than Tim.
Time that Albert took for the remaining 30 km of the trip
= 2
13 -
13 -
13 = 1
23 h
Albert's average speed
= 30 ÷ 1
23 = 18 km/h
Answer(s): (a) 07 10; (b) 18 km/h