At 7 a.m., Natalie and Rachel raced off together from the starting point of a track. Natalie ran at an average speed of 2 m/s. Rachel ran at an average speed of 4 m/s. Upon reaching the end of the track, Rachel rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 7.30 a.m., Natalie met Rachel.

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 Natalie ran = 30 min
Duration that Rachel ran = 30 -  6 = 24 min

1 min = 60 s

24 min = 24 x 60 = 1440 s
30 min = 30 x 60 = 1800 s

Distance that Natalie ran
= 2 x 1800
= 3600 m

Distance that Rachel ran
= 4 x 1440
= 5760 m

Distance that Natalie and Rachel ran
= 3600 + 5760
= 9360 m

1000 m = 1 km

9360 m = 9360 ÷ 1000 = 9.36 km

(b)
Length of the trail
= 9.36 ÷ 2
= 4.68 km

Answer(s): (a) 9.36 km; (b) 4.68 km