At 7 a.m., Fiona and Sarah raced off together from the starting point of a route. Fiona ran at an average speed of 1 m/s. Sarah ran at an average speed of 3 m/s. Upon reaching the end of the route, Sarah rested for 6 minutes. She then immediately ran back along the same route at 3 m/s. At 7.35 a.m., Fiona met Sarah.

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 7 a.m. to 7.35 a.m. = 35 min

Duration that Fiona ran = 35 min
Duration that Sarah 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 Fiona ran
= 1 x 2100
= 2100 m

Distance that Sarah ran
= 3 x 1740
= 5220 m

Distance that Fiona and Sarah ran
= 2100 + 5220
= 7320 m

1000 m = 1 km

7320 m = 7320 ÷ 1000 = 7.32 km

(b)
Length of the trail
= 7.32 ÷ 2
= 3.66 km

Answer(s): (a) 7.32 km; (b) 3.66 km