At 10 a.m., Marion and Jane raced off together from the starting point of a track. Marion ran at an average speed of 3 m/s. Jane ran at an average speed of 4 m/s. Upon reaching the end of the track, Jane rested for 5 minutes. She then immediately ran back along the same route at 4 m/s. At 10.25 a.m., Marion met Jane.

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 10.25 a.m. = 25 min

Duration that Marion ran = 25 min
Duration that Jane ran = 25 -  5 = 20 min

1 min = 60 s

20 min = 20 x 60 = 1200 s
25 min = 25 x 60 = 1500 s

Distance that Marion ran
= 3 x 1500
= 4500 m

Distance that Jane ran
= 4 x 1200
= 4800 m

Distance that Marion and Jane ran
= 4500 + 4800
= 9300 m

1000 m = 1 km

9300 m = 9300 ÷ 1000 = 9.3 km

(b)
Length of the trail
= 9.3 ÷ 2
= 4.65 km

Answer(s): (a) 9.3 km; (b) 4.65 km