At 11 a.m., Olivia and Ivory raced off together from the starting point of a pathway. Olivia ran at an average speed of 2 m/s. Ivory ran at an average speed of 3 m/s. Upon reaching the end of the pathway, Ivory rested for 5 minutes. She then immediately ran back along the same route at 3 m/s. At 11.25 a.m., Olivia met Ivory.

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 11 a.m. to 11.25 a.m. = 25 min

Duration that Olivia ran = 25 min
Duration that Ivory ran = 25 -  5 = 20 min

1 min = 60 s

20 min = 20 x 60 = 1200 s
25 min = 25 x 60 = 1500 s

Distance that Olivia ran
= 2 x 1500
= 3000 m

Distance that Ivory ran
= 3 x 1200
= 3600 m

Distance that Olivia and Ivory ran
= 3000 + 3600
= 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