At 9 a.m., Kathy and Kylie raced off together from the starting point of a course. Kathy ran at an average speed of 3 m/s. Kylie ran at an average speed of 4 m/s. Upon reaching the end of the course, Kylie rested for 4 minutes. She then immediately ran back along the same route at 4 m/s. At 9.25 a.m., Kathy met Kylie.

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 9 a.m. to 9.25 a.m. = 25 min

Duration that Kathy ran = 25 min
Duration that Kylie ran = 25 -  4 = 21 min

1 min = 60 s

21 min = 21 x 60 = 1260 s
25 min = 25 x 60 = 1500 s

Distance that Kathy ran
= 3 x 1500
= 4500 m

Distance that Kylie ran
= 4 x 1260
= 5040 m

Distance that Kathy and Kylie ran
= 4500 + 5040
= 9540 m

1000 m = 1 km

9540 m = 9540 ÷ 1000 = 9.54 km

(b)
Length of the trail
= 9.54 ÷ 2
= 4.77 km

Answer(s): (a) 9.54 km; (b) 4.77 km