PSLE
Vina and Mara started jogging from the same point of the 10 km track round a housing estate. They started at the same time but in opposite directions. Vina jogged past Mara after 8 km. Both of them did not change their speeds throughout. Vina took 20 min to complete one round. What was Mara's jogging speed in m/min?
Distance that Mara jogged when they passed each other
= 10 - 8
= 2 km

Time that Vina took to jog 10 km = 20 min

Time that Vina took to jog 1 km
= 20 ÷ 10
= 2 min

Time that Vina took to jog 8 km
= 8 x 2
= 16 min

When Vina took 16 min to jog 8 km, Mara took the same time to jog 2 km.

1 km = 1000 m
2 km = 2000 m

Mara's jogging speed
= 2000 ÷ 16
= 125 m/min

Answer(s): 125 m/min