Sabrina started jogging from the temple to the reservoir at a speed of 108 m/min at 6 a.m. Her cousin started jogging from the temple later. They were beside each other at 6.35 a.m. and her cousin reached the reservoir at 7 a.m. while Sabrina was still 1800 m away. If both of them travelled at a constant speed throughout the journey, what time did her cousin leave the temple?
1 h = 60 min

From 6 a.m. to 7 a.m. = 1 h
From 6.35 a.m. to 7 a.m. = 25 min

Distance between the temple and the reservoir
= 60 x 108 + 1800
= 6480 + 1800
= 8280 m

Distance that Sabrina's cousin had to cover to catch up with Sabrina
= 35 x 108
= 3780 m

Distance that Sabrina's cousin travelled to the reservoir after catching up with Sabrina
= 8280 - 3780
= 4500 m

Since Sabrina's cousin jogged 4500 m in 35 min,
Sabrina's cousin average speed
= 4500 ÷ 25
= 180 m/min

Duration that Sabrina's cousin took to jog to the reservoir
= 8280 ÷ 180
= 46 min

Time that Sabrina's cousin left the temple:
46 min before 7 a.m. = 6.14 a.m.

Answer(s): 6.14 a.m.