At 8 a.m., Anna and Gillian raced off together from the starting point of a route. Anna ran at an average speed of 1 m/s. Gillian ran at an average speed of 2 m/s. Upon reaching the end of the route, Gillian rested for 4 minutes. She then immediately ran back along the same route at 2 m/s. At 8.50 a.m., Anna met Gillian.

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 8.50 a.m. = 50 min

Duration that Anna ran = 50 min
Duration that Gillian ran = 50 -  4 = 46 min

1 min = 60 s

46 min = 46 x 60 = 2760 s
50 min = 50 x 60 = 3000 s

Distance that Anna ran
= 1 x 3000
= 3000 m

Distance that Gillian ran
= 2 x 2760
= 5520 m

Distance that Anna and Gillian ran
= 3000 + 5520
= 8520 m

1000 m = 1 km

8520 m = 8520 ÷ 1000 = 8.52 km

(b)
Length of the trail
= 8.52 ÷ 2
= 4.26 km

Answer(s): (a) 8.52 km; (b) 4.26 km