At 8 a.m., Tammy and Betty raced off together from the starting point of a track. Tammy ran at an average speed of 3 m/s. Betty ran at an average speed of 4 m/s. Upon reaching the end of the track, Betty rested for 4 minutes. She then immediately ran back along the same route at 4 m/s. At 8.25 a.m., Tammy met Betty.
- 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 8.25 a.m. = 25 min
Duration that Tammy ran = 25 min
Duration that Betty ran = 25 - 4 = 21 min
1 min = 60 s
21 min = 21 x 60 = 1260 s
25 min = 25 x 60 = 1500 s
Distance that Tammy ran
= 3 x 1500
= 4500 m
Distance that Betty ran
= 4 x 1260
= 5040 m
Distance that Tammy and Betty ran
= 4500 + 5040
= 9540 m
1000 m = 1 km
9540 m = 9540 ÷ 1000 = 9.54 km
(b)
Length of the trail
= 9.54 ÷ 2
= 4.77 km
Answer(s): (a) 9.54 km; (b) 4.77 km