At 10 a.m., Hilda and Penelope raced off together from the starting point of a pathway. Hilda ran at an average speed of 2 m/s. Penelope ran at an average speed of 4 m/s. Upon reaching the end of the pathway, Penelope rested for 5 minutes. She then immediately ran back along the same route at 4 m/s. At 10.45 a.m., Hilda met Penelope.

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 10.45 a.m. = 45 min

Duration that Hilda ran = 45 min
Duration that Penelope ran = 45 -  5 = 40 min

1 min = 60 s

40 min = 40 x 60 = 2400 s
45 min = 45 x 60 = 2700 s

Distance that Hilda ran
= 2 x 2700
= 5400 m

Distance that Penelope ran
= 4 x 2400
= 9600 m

Distance that Hilda and Penelope ran
= 5400 + 9600
= 15000 m

1000 m = 1 km

15000 m = 15000 ÷ 1000 = 15 km

(b)
Length of the trail
= 15 ÷ 2
= 7.5 km

Answer(s): (a) 15 km; (b) 7.5 km