PSLE
Jane and Ginny started jogging from the same point of the 12 km track round a housing estate. They started at the same time but in opposite directions. Jane jogged past Ginny after 10 km. Both of them did not change their speeds throughout. Jane took 15 min to complete one round. What was Ginny's jogging speed in m/min?
Distance that Ginny jogged when they passed each other
= 12 - 10
= 2 km

Time that Jane took to jog 12 km = 15 min

Time that Jane took to jog 1 km
= 15 ÷ 12
= 1.25 min

Time that Jane took to jog 10 km
= 10 x 1.25
= 12.5 min

When Jane took 12.5 min to jog 10 km, Ginny took the same time to jog 2 km.

1 km = 1000 m
2 km = 2000 m

Ginny's jogging speed
= 2000 ÷ 12.5
= 160 m/min

Answer(s): 160 m/min