At 11 a.m., Cathy and Abi raced off together from the starting point of a path. Cathy ran at an average speed of 2 m/s. Abi ran at an average speed of 4 m/s. Upon reaching the end of the path, Abi rested for 4 minutes. She then immediately ran back along the same route at 4 m/s. At 11.30 a.m., Cathy met Abi.

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 11.30 a.m. = 30 min

Duration that Cathy ran = 30 min
Duration that Abi ran = 30 -  4 = 26 min

1 min = 60 s

26 min = 26 x 60 = 1560 s
30 min = 30 x 60 = 1800 s

Distance that Cathy ran
= 2 x 1800
= 3600 m

Distance that Abi ran
= 4 x 1560
= 6240 m

Distance that Cathy and Abi ran
= 3600 + 6240
= 9840 m

1000 m = 1 km

9840 m = 9840 ÷ 1000 = 9.84 km

(b)
Length of the trail
= 9.84 ÷ 2
= 4.92 km

Answer(s): (a) 9.84 km; (b) 4.92 km