At 11 a.m., Ivory and Xylia raced off together from the starting point of a route. Ivory ran at an average speed of 2 m/s. Xylia ran at an average speed of 4 m/s. Upon reaching the end of the route, Xylia rested for 5 minutes. She then immediately ran back along the same route at 4 m/s. At 11.50 a.m., Ivory met Xylia.
- 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 11.50 a.m. = 50 min
Duration that Ivory ran = 50 min
Duration that Xylia ran = 50 - 5 = 45 min
1 min = 60 s
45 min = 45 x 60 = 2700 s
50 min = 50 x 60 = 3000 s
Distance that Ivory ran
= 2 x 3000
= 6000 m
Distance that Xylia ran
= 4 x 2700
= 10800 m
Distance that Ivory and Xylia ran
= 6000 + 10800
= 16800 m
1000 m = 1 km
16800 m = 16800 ÷ 1000 = 16.8 km
(b)
Length of the trail
= 16.8 ÷ 2
= 8.4 km
Answer(s): (a) 16.8 km; (b) 8.4 km