At 8 a.m., Lucy and Raeann raced off together from the starting point of a pathway. Lucy ran at an average speed of 3 m/s. Raeann ran at an average speed of 4 m/s. Upon reaching the end of the pathway, Raeann rested for 5 minutes. She then immediately ran back along the same route at 4 m/s. At 8.40 a.m., Lucy met Raeann.

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 8 a.m. to 8.40 a.m. = 40 min

Duration that Lucy ran = 40 min
Duration that Raeann ran = 40 -  5 = 35 min

1 min = 60 s

35 min = 35 x 60 = 2100 s
40 min = 40 x 60 = 2400 s

Distance that Lucy ran
= 3 x 2400
= 7200 m

Distance that Raeann ran
= 4 x 2100
= 8400 m

Distance that Lucy and Raeann ran
= 7200 + 8400
= 15600 m

1000 m = 1 km

15600 m = 15600 ÷ 1000 = 15.6 km

(b)
Length of the trail
= 15.6 ÷ 2
= 7.8 km

Answer(s): (a) 15.6 km; (b) 7.8 km