At 10 a.m., Sarah and Gabby raced off together from the starting point of a path. Sarah ran at an average speed of 1 m/s. Gabby ran at an average speed of 4 m/s. Upon reaching the end of the path, Gabby rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 10.35 a.m., Sarah met Gabby.

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 10.35 a.m. = 35 min

Duration that Sarah ran = 35 min
Duration that Gabby ran = 35 -  6 = 29 min

1 min = 60 s

29 min = 29 x 60 = 1740 s
35 min = 35 x 60 = 2100 s

Distance that Sarah ran
= 1 x 2100
= 2100 m

Distance that Gabby ran
= 4 x 1740
= 6960 m

Distance that Sarah and Gabby ran
= 2100 + 6960
= 9060 m

1000 m = 1 km

9060 m = 9060 ÷ 1000 = 9.06 km

(b)
Length of the trail
= 9.06 ÷ 2
= 4.53 km

Answer(s): (a) 9.06 km; (b) 4.53 km