At 9 a.m., Barbara and Natalie raced off together from the starting point of a pathway. Barbara ran at an average speed of 1 m/s. Natalie ran at an average speed of 2 m/s. Upon reaching the end of the pathway, Natalie rested for 5 minutes. She then immediately ran back along the same route at 2 m/s. At 9.40 a.m., Barbara met Natalie.

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 9.40 a.m. = 40 min

Duration that Barbara ran = 40 min
Duration that Natalie ran = 40 -  5 = 35 min

1 min = 60 s

35 min = 35 x 60 = 2100 s
40 min = 40 x 60 = 2400 s

Distance that Barbara ran
= 1 x 2400
= 2400 m

Distance that Natalie ran
= 2 x 2100
= 4200 m

Distance that Barbara and Natalie ran
= 2400 + 4200
= 6600 m

1000 m = 1 km

6600 m = 6600 ÷ 1000 = 6.6 km

(b)
Length of the trail
= 6.6 ÷ 2
= 3.3 km

Answer(s): (a) 6.6 km; (b) 3.3 km