At 11 a.m., Gem and Mary raced off together from the starting point of a track. Gem ran at an average speed of 1 m/s. Mary ran at an average speed of 2 m/s. Upon reaching the end of the track, Mary rested for 4 minutes. She then immediately ran back along the same route at 2 m/s. At 11.25 a.m., Gem met Mary.
- 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 11.25 a.m. = 25 min
Duration that Gem ran = 25 min
Duration that Mary 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 Gem ran
= 1 x 1500
= 1500 m
Distance that Mary ran
= 2 x 1260
= 2520 m
Distance that Gem and Mary ran
= 1500 + 2520
= 4020 m
1000 m = 1 km
4020 m = 4020 ÷ 1000 = 4.02 km
(b)
Length of the trail
= 4.02 ÷ 2
= 2.01 km
Answer(s): (a) 4.02 km; (b) 2.01 km