PSLE
Gem and Jane started jogging from the same point of the 12 km track round a nature reserve. They started at the same time but in opposite directions. Gem jogged past Jane after 10 km. Both of them did not change their speeds throughout. Gem took 15 min to complete one round. What was Jane's jogging speed in m/min?
Distance that Jane jogged when they passed each other
= 12 - 10
= 2 km

Time that Gem took to jog 12 km = 15 min

Time that Gem took to jog 1 km
= 15 ÷ 12
= 1.25 min

Time that Gem took to jog 10 km
= 10 x 1.25
= 12.5 min

When Gem took 12.5 min to jog 10 km, Jane took the same time to jog 2 km.

1 km = 1000 m
2 km = 2000 m

Jane's jogging speed
= 2000 ÷ 12.5
= 160 m/min

Answer(s): 160 m/min