At 8 a.m., Diana and Erika raced off together from the starting point of a pathway. Diana ran at an average speed of 1 m/s. Erika ran at an average speed of 2 m/s. Upon reaching the end of the pathway, Erika rested for 3 minutes. She then immediately ran back along the same route at 2 m/s. At 8.25 a.m., Diana met Erika.

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 8 a.m. to 8.25 a.m. = 25 min

Duration that Diana ran = 25 min
Duration that Erika ran = 25 -  3 = 22 min

1 min = 60 s

22 min = 22 x 60 = 1320 s
25 min = 25 x 60 = 1500 s

Distance that Diana ran
= 1 x 1500
= 1500 m

Distance that Erika ran
= 2 x 1320
= 2640 m

Distance that Diana and Erika ran
= 1500 + 2640
= 4140 m

1000 m = 1 km

4140 m = 4140 ÷ 1000 = 4.14 km

(b)
Length of the trail
= 4.14 ÷ 2
= 2.07 km

Answer(s): (a) 4.14 km; (b) 2.07 km