At 7 a.m., Shannon and Jane raced off together from the starting point of a route. Shannon ran at an average speed of 1 m/s. Jane ran at an average speed of 4 m/s. Upon reaching the end of the route, Jane rested for 5 minutes. She then immediately ran back along the same route at 4 m/s. At 7.30 a.m., Shannon met Jane.

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 7.30 a.m. = 30 min

Duration that Shannon ran = 30 min
Duration that Jane ran = 30 -  5 = 25 min

1 min = 60 s

25 min = 25 x 60 = 1500 s
30 min = 30 x 60 = 1800 s

Distance that Shannon ran
= 1 x 1800
= 1800 m

Distance that Jane ran
= 4 x 1500
= 6000 m

Distance that Shannon and Jane ran
= 1800 + 6000
= 7800 m

1000 m = 1 km

7800 m = 7800 ÷ 1000 = 7.8 km

(b)
Length of the trail
= 7.8 ÷ 2
= 3.9 km

Answer(s): (a) 7.8 km; (b) 3.9 km