At 7 a.m., Jade and Rachel raced off together from the starting point of a path. Jade ran at an average speed of 3 m/s. Rachel ran at an average speed of 4 m/s. Upon reaching the end of the path, Rachel rested for 3 minutes. She then immediately ran back along the same route at 4 m/s. At 7.50 a.m., Jade met Rachel.

1. Find the total distance covered by the two runners when they met each other. Express your answer in km.
2. Find the length of the trail in km.

(a)
From 7 a.m. to 7.50 a.m. = 50 min

Duration that Jade ran = 50 min
Duration that Rachel 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 Jade ran
= 3 x 3000
= 9000 m

Distance that Rachel ran
= 4 x 2820
= 11280 m

Distance that Jade and Rachel ran
= 9000 + 11280
= 20280 m

1000 m = 1 km

20280 m = 20280 ÷ 1000 = 20.28 km

(b)
Length of the trail
= 20.28 ÷ 2
= 10.14 km

Answer(s): (a) 20.28 km; (b) 10.14 km