At 8 a.m., Cindy and Kathy raced off together from the starting point of a pathway. Cindy ran at an average speed of 2 m/s. Kathy ran at an average speed of 4 m/s. Upon reaching the end of the pathway, Kathy rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 8.25 a.m., Cindy met Kathy.

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 8 a.m. to 8.25 a.m. = 25 min

Duration that Cindy ran = 25 min
Duration that Kathy 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 Cindy ran
= 2 x 1500
= 3000 m

Distance that Kathy ran
= 4 x 1140
= 4560 m

Distance that Cindy and Kathy ran
= 3000 + 4560
= 7560 m

1000 m = 1 km

7560 m = 7560 ÷ 1000 = 7.56 km

(b)
Length of the trail
= 7.56 ÷ 2
= 3.78 km

Answer(s): (a) 7.56 km; (b) 3.78 km