PSLE
Emma and Kitty 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. Emma jogged past Kitty after 10 km. Both of them did not change their speeds throughout. Emma took 15 min to complete one round. What was Kitty's jogging speed in m/min?
Distance that Kitty jogged when they passed each other
= 12 - 10
= 2 km

Time that Emma took to jog 12 km = 15 min

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

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

When Emma took 12.5 min to jog 10 km, Kitty took the same time to jog 2 km.

1 km = 1000 m
2 km = 2000 m

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

Answer(s): 160 m/min