Albert and Vaidev 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, Albert cycled faster than Vaidev. He arrived at the finishing point 20 minutes before Vaidev who was 5 km behind him. Vaidev 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 Albert's average speed for the remaining 43 km of the trip in km/h?
(a)
60 min = 1 h
20 min =
2060 h =
13 Vaidev's average speed
= 5 ÷
13 = 15 km/h
Time that Vaidev took for the trip
= 48 ÷ 15
= 3
315 h
= 3
15 h
= 3 h 12 min
3 h 12 min before 07 25 is 04 13.
(b)
To find the time that Albert took for the remaining 43 km of the trip, we need to use the time that Vaidev took subtract that of the time taken for first 5 km and the time that Albert was faster than Vaidev.
Time that Albert took for the remaining 43 km of the trip
= 3
15 -
13 -
13 = 2
815 h
Albert's average speed
= 43 ÷ 2
815 = 16
3738 km/h
Answer(s): (a) 04 13; (b) 16
3738 km/h