At 11 a.m., Penelope and Anna raced off together from the starting point of a path. Penelope ran at an average speed of 2 m/s. Anna ran at an average speed of 4 m/s. Upon reaching the end of the path, Anna rested for 3 minutes. She then immediately ran back along the same route at 4 m/s. At 11.35 a.m., Penelope met Anna.

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 11.35 a.m. = 35 min

Duration that Penelope ran = 35 min
Duration that Anna ran = 35 -  3 = 32 min

1 min = 60 s

32 min = 32 x 60 = 1920 s
35 min = 35 x 60 = 2100 s

Distance that Penelope ran
= 2 x 2100
= 4200 m

Distance that Anna ran
= 4 x 1920
= 7680 m

Distance that Penelope and Anna ran
= 4200 + 7680
= 11880 m

1000 m = 1 km

11880 m = 11880 ÷ 1000 = 11.88 km

(b)
Length of the trail
= 11.88 ÷ 2
= 5.94 km

Answer(s): (a) 11.88 km; (b) 5.94 km