PSLE
Nora and Ginny started jogging from the same point of the 12 km track round a nature reserve. They started at the same time but in opposite directions. Nora jogged past Ginny after 10 km. Both of them did not change their speeds throughout. Nora 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 Nora took to jog 12 km = 15 min

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

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

When Nora 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