At 10 a.m., Gwen and Joelle raced off together from the starting point of a route. Gwen ran at an average speed of 3 m/s. Joelle ran at an average speed of 4 m/s. Upon reaching the end of the route, Joelle rested for 4 minutes. She then immediately ran back along the same route at 4 m/s. At 10.45 a.m., Gwen met Joelle.

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 10 a.m. to 10.45 a.m. = 45 min

Duration that Gwen ran = 45 min
Duration that Joelle ran = 45 -  4 = 41 min

1 min = 60 s

41 min = 41 x 60 = 2460 s
45 min = 45 x 60 = 2700 s

Distance that Gwen ran
= 3 x 2700
= 8100 m

Distance that Joelle ran
= 4 x 2460
= 9840 m

Distance that Gwen and Joelle ran
= 8100 + 9840
= 17940 m

1000 m = 1 km

17940 m = 17940 ÷ 1000 = 17.94 km

(b)
Length of the trail
= 17.94 ÷ 2
= 8.97 km

Answer(s): (a) 17.94 km; (b) 8.97 km