At 7 a.m., Min and Gillian raced off together from the starting point of a path. Min ran at an average speed of 3 m/s. Gillian ran at an average speed of 4 m/s. Upon reaching the end of the path, Gillian rested for 3 minutes. She then immediately ran back along the same route at 4 m/s. At 7.30 a.m., Min 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 7 a.m. to 7.30 a.m. = 30 min

Duration that Min ran = 30 min
Duration that Gillian ran = 30 -  3 = 27 min

1 min = 60 s

27 min = 27 x 60 = 1620 s
30 min = 30 x 60 = 1800 s

Distance that Min ran
= 3 x 1800
= 5400 m

Distance that Gillian ran
= 4 x 1620
= 6480 m

Distance that Min and Gillian ran
= 5400 + 6480
= 11880 m

1000 m = 1 km

11880 m = 11880 ÷ 1000 = 11.88 km

(b)
Length of the trail
= 11.88 ÷ 2
= 5.94 km

Answer(s): (a) 11.88 km; (b) 5.94 km