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

Time that Sophia took to jog 15 km = 30 min

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

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

When Sophia took 24 min to jog 12 km, Chloe took the same time to jog 3 km.

1 km = 1000 m
3 km = 3000 m

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

Answer(s): 125 m/min