At 9 a.m., Cindy and Nicole raced off together from the starting point of a course. Cindy ran at an average speed of 1 m/s. Nicole ran at an average speed of 3 m/s. Upon reaching the end of the course, Nicole rested for 4 minutes. She then immediately ran back along the same route at 3 m/s. At 9.45 a.m., Cindy met Nicole.

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 9.45 a.m. = 45 min

Duration that Cindy ran = 45 min
Duration that Nicole ran = 45 -  4 = 41 min

1 min = 60 s

41 min = 41 x 60 = 2460 s
45 min = 45 x 60 = 2700 s

Distance that Cindy ran
= 1 x 2700
= 2700 m

Distance that Nicole ran
= 3 x 2460
= 7380 m

Distance that Cindy and Nicole ran
= 2700 + 7380
= 10080 m

1000 m = 1 km

10080 m = 10080 ÷ 1000 = 10.08 km

(b)
Length of the trail
= 10.08 ÷ 2
= 5.04 km

Answer(s): (a) 10.08 km; (b) 5.04 km