At 10 a.m., Eva and Irene raced off together from the starting point of a track. Eva ran at an average speed of 3 m/s. Irene ran at an average speed of 4 m/s. Upon reaching the end of the track, Irene rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 10.30 a.m., Eva met Irene.

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 10.30 a.m. = 30 min

Duration that Eva ran = 30 min
Duration that Irene 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 Eva ran
= 3 x 1800
= 5400 m

Distance that Irene ran
= 4 x 1440
= 5760 m

Distance that Eva and Irene ran
= 5400 + 5760
= 11160 m

1000 m = 1 km

11160 m = 11160 ÷ 1000 = 11.16 km

(b)
Length of the trail
= 11.16 ÷ 2
= 5.58 km

Answer(s): (a) 11.16 km; (b) 5.58 km