At 7 a.m., Nora and Betty raced off together from the starting point of a path. Nora ran at an average speed of 1 m/s. Betty ran at an average speed of 3 m/s. Upon reaching the end of the path, Betty rested for 6 minutes. She then immediately ran back along the same route at 3 m/s. At 7.50 a.m., Nora met Betty.

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 7.50 a.m. = 50 min

Duration that Nora ran = 50 min
Duration that Betty ran = 50 -  6 = 44 min

1 min = 60 s

44 min = 44 x 60 = 2640 s
50 min = 50 x 60 = 3000 s

Distance that Nora ran
= 1 x 3000
= 3000 m

Distance that Betty ran
= 3 x 2640
= 7920 m

Distance that Nora and Betty ran
= 3000 + 7920
= 10920 m

1000 m = 1 km

10920 m = 10920 ÷ 1000 = 10.92 km

(b)
Length of the trail
= 10.92 ÷ 2
= 5.46 km

Answer(s): (a) 10.92 km; (b) 5.46 km