At 9 a.m., Barbara and Irene raced off together from the starting point of a pathway. Barbara ran at an average speed of 2 m/s. Irene ran at an average speed of 3 m/s. Upon reaching the end of the pathway, Irene rested for 5 minutes. She then immediately ran back along the same route at 3 m/s. At 9.50 a.m., Barbara met Irene.

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 9.50 a.m. = 50 min

Duration that Barbara ran = 50 min
Duration that Irene ran = 50 -  5 = 45 min

1 min = 60 s

45 min = 45 x 60 = 2700 s
50 min = 50 x 60 = 3000 s

Distance that Barbara ran
= 2 x 3000
= 6000 m

Distance that Irene ran
= 3 x 2700
= 8100 m

Distance that Barbara and Irene ran
= 6000 + 8100
= 14100 m

1000 m = 1 km

14100 m = 14100 ÷ 1000 = 14.1 km

(b)
Length of the trail
= 14.1 ÷ 2
= 7.05 km

Answer(s): (a) 14.1 km; (b) 7.05 km