At 10 a.m., Gwen and Marion raced off together from the starting point of a course. Gwen ran at an average speed of 2 m/s. Marion ran at an average speed of 4 m/s. Upon reaching the end of the course, Marion rested for 4 minutes. She then immediately ran back along the same route at 4 m/s. At 10.35 a.m., Gwen met Marion.
- Find the total distance covered by the two runners when they met each other. Express your answer in km.
- Find the length of the trail in km.
(a)
From 10 a.m. to 10.35 a.m. = 35 min
Duration that Gwen ran = 35 min
Duration that Marion ran = 35 - 4 = 31 min
1 min = 60 s
31 min = 31 x 60 = 1860 s
35 min = 35 x 60 = 2100 s
Distance that Gwen ran
= 2 x 2100
= 4200 m
Distance that Marion ran
= 4 x 1860
= 7440 m
Distance that Gwen and Marion ran
= 4200 + 7440
= 11640 m
1000 m = 1 km
11640 m = 11640 ÷ 1000 = 11.64 km
(b)
Length of the trail
= 11.64 ÷ 2
= 5.82 km
Answer(s): (a) 11.64 km; (b) 5.82 km