At 10 a.m., Natalie and Yoko raced off together from the starting point of a route. Natalie ran at an average speed of 3 m/s. Yoko ran at an average speed of 4 m/s. Upon reaching the end of the route, Yoko rested for 3 minutes. She then immediately ran back along the same route at 4 m/s. At 10.25 a.m., Natalie met Yoko.

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 10.25 a.m. = 25 min

Duration that Natalie ran = 25 min
Duration that Yoko ran = 25 -  3 = 22 min

1 min = 60 s

22 min = 22 x 60 = 1320 s
25 min = 25 x 60 = 1500 s

Distance that Natalie ran
= 3 x 1500
= 4500 m

Distance that Yoko ran
= 4 x 1320
= 5280 m

Distance that Natalie and Yoko ran
= 4500 + 5280
= 9780 m

1000 m = 1 km

9780 m = 9780 ÷ 1000 = 9.78 km

(b)
Length of the trail
= 9.78 ÷ 2
= 4.89 km

Answer(s): (a) 9.78 km; (b) 4.89 km