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

Time that Ava took to jog 15 km = 30 min

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

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

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

1 km = 1000 m
3 km = 3000 m

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

Answer(s): 125 m/min