PSLE
Zoe and Leah started jogging from the same point of the 15 km track round a lake. They started at the same time but in opposite directions. Zoe jogged past Leah after 10 km. Both of them did not change their speeds throughout. Zoe took 30 min to complete one round. What was Leah's jogging speed in m/min?
Distance that Leah jogged when they passed each other
= 15 - 10
= 5 km

Time that Zoe took to jog 15 km = 30 min

Time that Zoe took to jog 1 km
= 30 ÷ 15
= 2 min

Time that Zoe took to jog 10 km
= 10 x 2
= 20 min

When Zoe took 20 min to jog 10 km, Leah took the same time to jog 5 km.

1 km = 1000 m
5 km = 5000 m

Leah's jogging speed
= 5000 ÷ 20
= 250 m/min

Answer(s): 250 m/min