Risa and Ahmad started running together along a cross country track. When Ahmad completed the track in 24 minutes, Risa had run only
47 of the track. Risa’s average speed was 96 m/min slower than Ahmad’s.
- How long was the cross country track in m?
- Find Risa’s average speed in m/min.
(a)
When Ahmad completed the track:
Ahmad's distance = 7 u
Risa's distance = 4 u
Extra distance covered by Ahmad
= 7 u - 4 u
= 3 u
3 u = 96 x 24
3 u = 2304
1 u = 2304 ÷ 3 = 768
Distance of the cross country track
= 7 u
= 7 x 768
= 5376 m
(b)
Ahmad's speed
= 5376 ÷ 24
= 224 m/min
Risa's speed
= 224 - 96
= 128 m/min
Answer(s): (a) 5376 m; (b) 128 m/min