At 11 a.m., Jaslyn and Risa raced off together from the starting point of a path. Jaslyn ran at an average speed of 2 m/s. Risa ran at an average speed of 3 m/s. Upon reaching the end of the path, Risa rested for 3 minutes. She then immediately ran back along the same route at 3 m/s. At 11.35 a.m., Jaslyn met Risa.
- 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 11.35 a.m. = 35 min
Duration that Jaslyn ran = 35 min
Duration that Risa ran = 35 - 3 = 32 min
1 min = 60 s
32 min = 32 x 60 = 1920 s
35 min = 35 x 60 = 2100 s
Distance that Jaslyn ran
= 2 x 2100
= 4200 m
Distance that Risa ran
= 3 x 1920
= 5760 m
Distance that Jaslyn and Risa ran
= 4200 + 5760
= 9960 m
1000 m = 1 km
9960 m = 9960 ÷ 1000 = 9.96 km
(b)
Length of the trail
= 9.96 ÷ 2
= 4.98 km
Answer(s): (a) 9.96 km; (b) 4.98 km