At 11 a.m., Abi and Cindy raced off together from the starting point of a route. Abi ran at an average speed of 1 m/s. Cindy ran at an average speed of 3 m/s. Upon reaching the end of the route, Cindy rested for 5 minutes. She then immediately ran back along the same route at 3 m/s. At 11.40 a.m., Abi met Cindy.
- 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 11 a.m. to 11.40 a.m. = 40 min
Duration that Abi ran = 40 min
Duration that Cindy ran = 40 - 5 = 35 min
1 min = 60 s
35 min = 35 x 60 = 2100 s
40 min = 40 x 60 = 2400 s
Distance that Abi ran
= 1 x 2400
= 2400 m
Distance that Cindy ran
= 3 x 2100
= 6300 m
Distance that Abi and Cindy ran
= 2400 + 6300
= 8700 m
1000 m = 1 km
8700 m = 8700 ÷ 1000 = 8.7 km
(b)
Length of the trail
= 8.7 ÷ 2
= 4.35 km
Answer(s): (a) 8.7 km; (b) 4.35 km