At 11 a.m., Xandra and Cathy raced off together from the starting point of a course. Xandra ran at an average speed of 2 m/s. Cathy ran at an average speed of 4 m/s. Upon reaching the end of the course, Cathy rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 11.35 a.m., Xandra met Cathy.

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 11.35 a.m. = 35 min

Duration that Xandra ran = 35 min
Duration that Cathy ran = 35 -  6 = 29 min

1 min = 60 s

29 min = 29 x 60 = 1740 s
35 min = 35 x 60 = 2100 s

Distance that Xandra ran
= 2 x 2100
= 4200 m

Distance that Cathy ran
= 4 x 1740
= 6960 m

Distance that Xandra and Cathy ran
= 4200 + 6960
= 11160 m

1000 m = 1 km

11160 m = 11160 ÷ 1000 = 11.16 km

(b)
Length of the trail
= 11.16 ÷ 2
= 5.58 km

Answer(s): (a) 11.16 km; (b) 5.58 km