At 11 a.m., Opal and Abi raced off together from the starting point of a route. Opal ran at an average speed of 2 m/s. Abi ran at an average speed of 3 m/s. Upon reaching the end of the route, Abi rested for 6 minutes. She then immediately ran back along the same route at 3 m/s. At 11.50 a.m., Opal met Abi.

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 11.50 a.m. = 50 min

Duration that Opal ran = 50 min
Duration that Abi ran = 50 -  6 = 44 min

1 min = 60 s

44 min = 44 x 60 = 2640 s
50 min = 50 x 60 = 3000 s

Distance that Opal ran
= 2 x 3000
= 6000 m

Distance that Abi ran
= 3 x 2640
= 7920 m

Distance that Opal and Abi ran
= 6000 + 7920
= 13920 m

1000 m = 1 km

13920 m = 13920 ÷ 1000 = 13.92 km

(b)
Length of the trail
= 13.92 ÷ 2
= 6.96 km

Answer(s): (a) 13.92 km; (b) 6.96 km