At 10 a.m., Xuan and Winnie raced off together from the starting point of a pathway. Xuan ran at an average speed of 2 m/s. Winnie ran at an average speed of 4 m/s. Upon reaching the end of the pathway, Winnie rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 10.30 a.m., Xuan met Winnie.

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 10 a.m. to 10.30 a.m. = 30 min

Duration that Xuan ran = 30 min
Duration that Winnie ran = 30 -  6 = 24 min

1 min = 60 s

24 min = 24 x 60 = 1440 s
30 min = 30 x 60 = 1800 s

Distance that Xuan ran
= 2 x 1800
= 3600 m

Distance that Winnie ran
= 4 x 1440
= 5760 m

Distance that Xuan and Winnie ran
= 3600 + 5760
= 9360 m

1000 m = 1 km

9360 m = 9360 ÷ 1000 = 9.36 km

(b)
Length of the trail
= 9.36 ÷ 2
= 4.68 km

Answer(s): (a) 9.36 km; (b) 4.68 km