At 7 a.m., Xylia and Roshel raced off together from the starting point of a path. Xylia ran at an average speed of 2 m/s. Roshel ran at an average speed of 4 m/s. Upon reaching the end of the path, Roshel rested for 5 minutes. She then immediately ran back along the same route at 4 m/s. At 7.25 a.m., Xylia met Roshel.

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 7 a.m. to 7.25 a.m. = 25 min

Duration that Xylia ran = 25 min
Duration that Roshel ran = 25 -  5 = 20 min

1 min = 60 s

20 min = 20 x 60 = 1200 s
25 min = 25 x 60 = 1500 s

Distance that Xylia ran
= 2 x 1500
= 3000 m

Distance that Roshel ran
= 4 x 1200
= 4800 m

Distance that Xylia and Roshel ran
= 3000 + 4800
= 7800 m

1000 m = 1 km

7800 m = 7800 ÷ 1000 = 7.8 km

(b)
Length of the trail
= 7.8 ÷ 2
= 3.9 km

Answer(s): (a) 7.8 km; (b) 3.9 km