Pamela started jogging from the market to the park at a speed of 114 m/min at 7 a.m. Her brother started jogging from the market later. They were beside each other at 7.35 a.m. and her brother reached the park at 8 a.m. while Pamela was still 1900 m away. If both of them travelled at a constant speed throughout the journey, what time did her brother leave the market?
1 h = 60 min

From 7 a.m. to 8 a.m. = 1 h
From 7.35 a.m. to 8 a.m. = 25 min

Distance between the market and the park
= 60 x 114 + 1900
= 6840 + 1900
= 8740 m

Distance that Pamela's brother had to cover to catch up with Pamela
= 35 x 114
= 3990 m

Distance that Pamela's brother travelled to the park after catching up with Pamela
= 8740 - 3990
= 4750 m

Since Pamela's brother jogged 4750 m in 35 min,
Pamela's brother average speed
= 4750 ÷ 25
= 190 m/min

Duration that Pamela's brother took to jog to the park
= 8740 ÷ 190
= 46 min

Time that Pamela's brother left the market:
46 min before 8 a.m. = 7.14 a.m.

Answer(s): 7.14 a.m.