At 11 a.m., Diana and Roshel raced off together from the starting point of a pathway. Diana ran at an average speed of 1 m/s. Roshel ran at an average speed of 4 m/s. Upon reaching the end of the pathway, Roshel rested for 3 minutes. She then immediately ran back along the same route at 4 m/s. At 11.25 a.m., Diana met Roshel.

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 Diana ran = 25 min
Duration that Roshel 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 Diana ran
= 1 x 1500
= 1500 m

Distance that Roshel ran
= 4 x 1320
= 5280 m

Distance that Diana and Roshel ran
= 1500 + 5280
= 6780 m

1000 m = 1 km

6780 m = 6780 ÷ 1000 = 6.78 km

(b)
Length of the trail
= 6.78 ÷ 2
= 3.39 km

Answer(s): (a) 6.78 km; (b) 3.39 km