At 10 a.m., Cindy and Nora raced off together from the starting point of a route. Cindy ran at an average speed of 2 m/s. Nora ran at an average speed of 3 m/s. Upon reaching the end of the route, Nora rested for 3 minutes. She then immediately ran back along the same route at 3 m/s. At 10.45 a.m., Cindy met Nora.
- 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 10.45 a.m. = 45 min
Duration that Cindy ran = 45 min
Duration that Nora ran = 45 - 3 = 42 min
1 min = 60 s
42 min = 42 x 60 = 2520 s
45 min = 45 x 60 = 2700 s
Distance that Cindy ran
= 2 x 2700
= 5400 m
Distance that Nora ran
= 3 x 2520
= 7560 m
Distance that Cindy and Nora ran
= 5400 + 7560
= 12960 m
1000 m = 1 km
12960 m = 12960 ÷ 1000 = 12.96 km
(b)
Length of the trail
= 12.96 ÷ 2
= 6.48 km
Answer(s): (a) 12.96 km; (b) 6.48 km