PSLE
Jem and Nora started jogging from the same point of the 15 km track round a lake. They started at the same time but in opposite directions. Jem jogged past Nora after 12 km. Both of them did not change their speeds throughout. Jem took 15 min to complete one round. What was Nora's jogging speed in m/min?
Distance that Nora jogged when they passed each other
= 15 - 12
= 3 km

Time that Jem took to jog 15 km = 15 min

Time that Jem took to jog 1 km
= 15 ÷ 15
= 1 min

Time that Jem took to jog 12 km
= 12 x 1
= 12 min

When Jem took 12 min to jog 12 km, Nora took the same time to jog 3 km.

1 km = 1000 m
3 km = 3000 m

Nora's jogging speed
= 3000 ÷ 12
= 250 m/min

Answer(s): 250 m/min