At 11 a.m., Fiona and Kimberly raced off together from the starting point of a route. Fiona ran at an average speed of 2 m/s. Kimberly ran at an average speed of 4 m/s. Upon reaching the end of the route, Kimberly rested for 5 minutes. She then immediately ran back along the same route at 4 m/s. At 11.40 a.m., Fiona met Kimberly.

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 11.40 a.m. = 40 min

Duration that Fiona ran = 40 min
Duration that Kimberly ran = 40 -  5 = 35 min

1 min = 60 s

35 min = 35 x 60 = 2100 s
40 min = 40 x 60 = 2400 s

Distance that Fiona ran
= 2 x 2400
= 4800 m

Distance that Kimberly ran
= 4 x 2100
= 8400 m

Distance that Fiona and Kimberly ran
= 4800 + 8400
= 13200 m

1000 m = 1 km

13200 m = 13200 ÷ 1000 = 13.2 km

(b)
Length of the trail
= 13.2 ÷ 2
= 6.6 km

Answer(s): (a) 13.2 km; (b) 6.6 km