At 11 a.m., Gillian and Wendy raced off together from the starting point of a course. Gillian ran at an average speed of 1 m/s. Wendy ran at an average speed of 4 m/s. Upon reaching the end of the course, Wendy rested for 3 minutes. She then immediately ran back along the same route at 4 m/s. At 11.50 a.m., Gillian met Wendy.
- 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 Gillian ran = 50 min
Duration that Wendy ran = 50 - 3 = 47 min
1 min = 60 s
47 min = 47 x 60 = 2820 s
50 min = 50 x 60 = 3000 s
Distance that Gillian ran
= 1 x 3000
= 3000 m
Distance that Wendy ran
= 4 x 2820
= 11280 m
Distance that Gillian and Wendy ran
= 3000 + 11280
= 14280 m
1000 m = 1 km
14280 m = 14280 ÷ 1000 = 14.28 km
(b)
Length of the trail
= 14.28 ÷ 2
= 7.14 km
Answer(s): (a) 14.28 km; (b) 7.14 km