At 7 a.m., Roshel and Kimberly raced off together from the starting point of a course. Roshel ran at an average speed of 1 m/s. Kimberly ran at an average speed of 3 m/s. Upon reaching the end of the course, Kimberly rested for 3 minutes. She then immediately ran back along the same route at 3 m/s. At 7.25 a.m., Roshel met Kimberly.

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 7.25 a.m. = 25 min

Duration that Roshel ran = 25 min
Duration that Kimberly ran = 25 -  3 = 22 min

1 min = 60 s

22 min = 22 x 60 = 1320 s
25 min = 25 x 60 = 1500 s

Distance that Roshel ran
= 1 x 1500
= 1500 m

Distance that Kimberly ran
= 3 x 1320
= 3960 m

Distance that Roshel and Kimberly ran
= 1500 + 3960
= 5460 m

1000 m = 1 km

5460 m = 5460 ÷ 1000 = 5.46 km

(b)
Length of the trail
= 5.46 ÷ 2
= 2.73 km

Answer(s): (a) 5.46 km; (b) 2.73 km