At 9 a.m., Yen and Natalie raced off together from the starting point of a path. Yen 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 path, Natalie rested for 4 minutes. She then immediately ran back along the same route at 2 m/s. At 9.50 a.m., Yen 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 9.50 a.m. = 50 min

Duration that Yen ran = 50 min
Duration that Natalie ran = 50 -  4 = 46 min

1 min = 60 s

46 min = 46 x 60 = 2760 s
50 min = 50 x 60 = 3000 s

Distance that Yen ran
= 1 x 3000
= 3000 m

Distance that Natalie ran
= 2 x 2760
= 5520 m

Distance that Yen and Natalie ran
= 3000 + 5520
= 8520 m

1000 m = 1 km

8520 m = 8520 ÷ 1000 = 8.52 km

(b)
Length of the trail
= 8.52 ÷ 2
= 4.26 km

Answer(s): (a) 8.52 km; (b) 4.26 km