Jane started jogging from the bistro to the garden at a speed of 96 m/min at 5 a.m. Her cousin started jogging from the bistro later. They were beside each other at 5.35 a.m. and her cousin reached the garden at 6 a.m. while Jane was still 1600 m away. If both of them travelled at a constant speed throughout the journey, what time did her cousin leave the bistro?
1 h = 60 min

From 5 a.m. to 6 a.m. = 1 h
From 5.35 a.m. to 6 a.m. = 25 min

Distance between the bistro and the garden
= 60 x 96 + 1600
= 5760 + 1600
= 7360 m

Distance that Jane's cousin had to cover to catch up with Jane
= 35 x 96
= 3360 m

Distance that Jane's cousin travelled to the garden after catching up with Jane
= 7360 - 3360
= 4000 m

Since Jane's cousin jogged 4000 m in 35 min,
Jane's cousin average speed
= 4000 ÷ 25
= 160 m/min

Duration that Jane's cousin took to jog to the garden
= 7360 ÷ 160
= 46 min

Time that Jane's cousin left the bistro:
46 min before 6 a.m. = 5.14 a.m.

Answer(s): 5.14 a.m.