At 9 a.m., Gillian and Joelle raced off together from the starting point of a track. Gillian ran at an average speed of 1 m/s. Joelle ran at an average speed of 3 m/s. Upon reaching the end of the track, Joelle rested for 3 minutes. She then immediately ran back along the same route at 3 m/s. At 9.50 a.m., Gillian met Joelle.

1. Find the total distance covered by the two runners when they met each other. Express your answer in km.
2. Find the length of the trail in km.

(a)
From 9 a.m. to 9.50 a.m. = 50 min

Duration that Gillian ran = 50 min
Duration that Joelle ran = 50 -  3 = 47 min

1 min = 60 s

47 min = 47 x 60 = 2820 s
50 min = 50 x 60 = 3000 s

Distance that Gillian ran
= 1 x 3000
= 3000 m

Distance that Joelle ran
= 3 x 2820
= 8460 m

Distance that Gillian and Joelle ran
= 3000 + 8460
= 11460 m

1000 m = 1 km

11460 m = 11460 ÷ 1000 = 11.46 km

(b)
Length of the trail
= 11.46 ÷ 2
= 5.73 km

Answer(s): (a) 11.46 km; (b) 5.73 km