Zane and Ian started on a 55-km cycling trip at the same time. They cycled at the same speed for first 10 km. For the remaining 45 km, Zane cycled faster than Ian. He arrived at the finishing point 24 minutes before Ian who was 10 km behind him. Ian did not change his speed throughout and completed it at 09 25.

1. At what time did the trip begin? Give the answer in 12-hour format.
2. What was Zane's average speed for the remaining 45 km of the trip in km/h?

(a)
60 min = 1 h
24 min =²⁴₆₀ h = ²₅ 

Ian's average speed
= 10 ÷ ²₅
= 25 km/h

Time that Ian took for the trip
= 55 ÷ 25
= 2⁵₂₅ h
= 2¹₅ h
= 2 h 12 min

2 h 12 min before 09 25 is 07 13.

(b)
To find the time that Zane took for the remaining 45 km of the trip, we need to use the time that Ian took subtract that of the time taken for first 10 km and the time that Zane was faster than Ian.

Time that Zane took for the remaining 45 km of the trip
= 2¹₅ - ²₅ - ²₅
= 1²₅ h

Zane's average speed
= 45 ÷ 1²₅
= 32¹₇ km/h

Answer(s): (a) 07 13; (b) 32¹₇ km/h