Hilda and Billy started running together along a cross country track. When Billy completed the track in 35 minutes, Hilda had run only
35 of the track. Hilda’s average speed was 98 m/min slower than Billy’s.
- How long was the cross country track in m?
- Find Hilda’s average speed in m/min.
(a)
When Billy completed the track:
Billy's distance = 5 u
Hilda's distance = 3 u
Extra distance covered by Billy
= 5 u - 3 u
= 2 u
2 u = 98 x 35
2 u = 3430
1 u = 3430 ÷ 2 = 1715
Distance of the cross country track
= 5 u
= 5 x 1715
= 8575 m
(b)
Billy's speed
= 8575 ÷ 35
= 245 m/min
Hilda's speed
= 245 - 98
= 147 m/min
Answer(s): (a) 8575 m; (b) 147 m/min