At 11 a.m., Yen and Cindy raced off together from the starting point of a path. Yen ran at an average speed of 1 m/s. Cindy ran at an average speed of 4 m/s. Upon reaching the end of the path, Cindy rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 11.25 a.m., Yen met Cindy.

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 11.25 a.m. = 25 min

Duration that Yen ran = 25 min
Duration that Cindy ran = 25 -  6 = 19 min

1 min = 60 s

19 min = 19 x 60 = 1140 s
25 min = 25 x 60 = 1500 s

Distance that Yen ran
= 1 x 1500
= 1500 m

Distance that Cindy ran
= 4 x 1140
= 4560 m

Distance that Yen and Cindy ran
= 1500 + 4560
= 6060 m

1000 m = 1 km

6060 m = 6060 ÷ 1000 = 6.06 km

(b)
Length of the trail
= 6.06 ÷ 2
= 3.03 km

Answer(s): (a) 6.06 km; (b) 3.03 km