At 11 a.m., Elyse and Xuan raced off together from the starting point of a track. Elyse ran at an average speed of 2 m/s. Xuan ran at an average speed of 3 m/s. Upon reaching the end of the track, Xuan rested for 5 minutes. She then immediately ran back along the same route at 3 m/s. At 11.45 a.m., Elyse met Xuan.

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 11 a.m. to 11.45 a.m. = 45 min

Duration that Elyse ran = 45 min
Duration that Xuan ran = 45 -  5 = 40 min

1 min = 60 s

40 min = 40 x 60 = 2400 s
45 min = 45 x 60 = 2700 s

Distance that Elyse ran
= 2 x 2700
= 5400 m

Distance that Xuan ran
= 3 x 2400
= 7200 m

Distance that Elyse and Xuan ran
= 5400 + 7200
= 12600 m

1000 m = 1 km

12600 m = 12600 ÷ 1000 = 12.6 km

(b)
Length of the trail
= 12.6 ÷ 2
= 6.3 km

Answer(s): (a) 12.6 km; (b) 6.3 km