At 10 a.m., Vanessa and Min raced off together from the starting point of a course. Vanessa ran at an average speed of 2 m/s. Min ran at an average speed of 4 m/s. Upon reaching the end of the course, Min rested for 4 minutes. She then immediately ran back along the same route at 4 m/s. At 10.35 a.m., Vanessa met Min.

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 10.35 a.m. = 35 min

Duration that Vanessa ran = 35 min
Duration that Min ran = 35 -  4 = 31 min

1 min = 60 s

31 min = 31 x 60 = 1860 s
35 min = 35 x 60 = 2100 s

Distance that Vanessa ran
= 2 x 2100
= 4200 m

Distance that Min ran
= 4 x 1860
= 7440 m

Distance that Vanessa and Min ran
= 4200 + 7440
= 11640 m

1000 m = 1 km

11640 m = 11640 ÷ 1000 = 11.64 km

(b)
Length of the trail
= 11.64 ÷ 2
= 5.82 km

Answer(s): (a) 11.64 km; (b) 5.82 km