Penelope and Charlie started running together along a cross country track. When Charlie completed the track in 50 minutes, Penelope had run only
47 of the track. Penelope’s average speed was 96 m/min slower than Charlie’s.
- How long was the cross country track in m?
- Find Penelope’s average speed in m/min.
(a)
When Charlie completed the track:
Charlie's distance = 7 u
Penelope's distance = 4 u
Extra distance covered by Charlie
= 7 u - 4 u
= 3 u
3 u = 96 x 50
3 u = 4800
1 u = 4800 ÷ 3 = 1600
Distance of the cross country track
= 7 u
= 7 x 1600
= 11200 m
(b)
Charlie's speed
= 11200 ÷ 50
= 224 m/min
Penelope's speed
= 224 - 96
= 128 m/min
Answer(s): (a) 11200 m; (b) 128 m/min