At 8 a.m., Emma and Zara raced off together from the starting point of a path. Emma ran at an average speed of 1 m/s. Zara ran at an average speed of 3 m/s. Upon reaching the end of the path, Zara rested for 3 minutes. She then immediately ran back along the same route at 3 m/s. At 8.30 a.m., Emma met Zara.

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 8 a.m. to 8.30 a.m. = 30 min

Duration that Emma ran = 30 min
Duration that Zara ran = 30 -  3 = 27 min

1 min = 60 s

27 min = 27 x 60 = 1620 s
30 min = 30 x 60 = 1800 s

Distance that Emma ran
= 1 x 1800
= 1800 m

Distance that Zara ran
= 3 x 1620
= 4860 m

Distance that Emma and Zara ran
= 1800 + 4860
= 6660 m

1000 m = 1 km

6660 m = 6660 ÷ 1000 = 6.66 km

(b)
Length of the trail
= 6.66 ÷ 2
= 3.33 km

Answer(s): (a) 6.66 km; (b) 3.33 km