At 7 a.m., Barbara and Linda raced off together from the starting point of a course. Barbara ran at an average speed of 2 m/s. Linda ran at an average speed of 4 m/s. Upon reaching the end of the course, Linda rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 7.50 a.m., Barbara met Linda.

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 Barbara ran = 50 min
Duration that Linda 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 Barbara ran
= 2 x 3000
= 6000 m

Distance that Linda ran
= 4 x 2640
= 10560 m

Distance that Barbara and Linda ran
= 6000 + 10560
= 16560 m

1000 m = 1 km

16560 m = 16560 ÷ 1000 = 16.56 km

(b)
Length of the trail
= 16.56 ÷ 2
= 8.28 km

Answer(s): (a) 16.56 km; (b) 8.28 km