At 7 a.m., Dana and Gwen raced off together from the starting point of a track. Dana ran at an average speed of 1 m/s. Gwen ran at an average speed of 4 m/s. Upon reaching the end of the track, Gwen rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 7.45 a.m., Dana met Gwen.

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 7 a.m. to 7.45 a.m. = 45 min

Duration that Dana ran = 45 min
Duration that Gwen ran = 45 -  6 = 39 min

1 min = 60 s

39 min = 39 x 60 = 2340 s
45 min = 45 x 60 = 2700 s

Distance that Dana ran
= 1 x 2700
= 2700 m

Distance that Gwen ran
= 4 x 2340
= 9360 m

Distance that Dana and Gwen ran
= 2700 + 9360
= 12060 m

1000 m = 1 km

12060 m = 12060 ÷ 1000 = 12.06 km

(b)
Length of the trail
= 12.06 ÷ 2
= 6.03 km

Answer(s): (a) 12.06 km; (b) 6.03 km