At 11 a.m., Lucy and Lynn raced off together from the starting point of a course. Lucy ran at an average speed of 1 m/s. Lynn ran at an average speed of 2 m/s. Upon reaching the end of the course, Lynn rested for 5 minutes. She then immediately ran back along the same route at 2 m/s. At 11.45 a.m., Lucy met Lynn.

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 11 a.m. to 11.45 a.m. = 45 min

Duration that Lucy ran = 45 min
Duration that Lynn ran = 45 -  5 = 40 min

1 min = 60 s

40 min = 40 x 60 = 2400 s
45 min = 45 x 60 = 2700 s

Distance that Lucy ran
= 1 x 2700
= 2700 m

Distance that Lynn ran
= 2 x 2400
= 4800 m

Distance that Lucy and Lynn ran
= 2700 + 4800
= 7500 m

1000 m = 1 km

7500 m = 7500 ÷ 1000 = 7.5 km

(b)
Length of the trail
= 7.5 ÷ 2
= 3.75 km

Answer(s): (a) 7.5 km; (b) 3.75 km