PSLE
Elsa and Candy started jogging from the same point of the 15 km track round a lake. They started at the same time but in opposite directions. Elsa jogged past Candy after 12 km. Both of them did not change their speeds throughout. Elsa took 30 min to complete one round. What was Candy's jogging speed in m/min?
Distance that Candy jogged when they passed each other
= 15 - 12
= 3 km

Time that Elsa took to jog 15 km = 30 min

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

Time that Elsa took to jog 12 km
= 12 x 2
= 24 min

When Elsa took 24 min to jog 12 km, Candy took the same time to jog 3 km.

1 km = 1000 m
3 km = 3000 m

Candy's jogging speed
= 3000 ÷ 24
= 125 m/min

Answer(s): 125 m/min