At 10 a.m., Marion and Gabby raced off together from the starting point of a course. Marion ran at an average speed of 1 m/s. Gabby ran at an average speed of 2 m/s. Upon reaching the end of the course, Gabby rested for 3 minutes. She then immediately ran back along the same route at 2 m/s. At 10.30 a.m., Marion met Gabby.

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 10.30 a.m. = 30 min

Duration that Marion ran = 30 min
Duration that Gabby ran = 30 -  3 = 27 min

1 min = 60 s

27 min = 27 x 60 = 1620 s
30 min = 30 x 60 = 1800 s

Distance that Marion ran
= 1 x 1800
= 1800 m

Distance that Gabby ran
= 2 x 1620
= 3240 m

Distance that Marion and Gabby ran
= 1800 + 3240
= 5040 m

1000 m = 1 km

5040 m = 5040 ÷ 1000 = 5.04 km

(b)
Length of the trail
= 5.04 ÷ 2
= 2.52 km

Answer(s): (a) 5.04 km; (b) 2.52 km