At 8 a.m., Marion and Rachel raced off together from the starting point of a path. Marion ran at an average speed of 3 m/s. Rachel ran at an average speed of 4 m/s. Upon reaching the end of the path, Rachel rested for 6 minutes. She then immediately ran back along the same route at 4 m/s. At 8.50 a.m., Marion met Rachel.
- 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 8 a.m. to 8.50 a.m. = 50 min
Duration that Marion ran = 50 min
Duration that Rachel 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 Marion ran
= 3 x 3000
= 9000 m
Distance that Rachel ran
= 4 x 2640
= 10560 m
Distance that Marion and Rachel ran
= 9000 + 10560
= 19560 m
1000 m = 1 km
19560 m = 19560 ÷ 1000 = 19.56 km
(b)
Length of the trail
= 19.56 ÷ 2
= 9.78 km
Answer(s): (a) 19.56 km; (b) 9.78 km