|
puppylover wrote:
This question came out in the math paper today.
Mei and Lin competed in a race. Mei ran at a speed of 20km/hr. When Lin had completed half of the distance, Mei had completed 3.5km more than her. If Mei reached at 10.45am, what time did Lin reach?
3.5 / 20 x 60 = 10.5 min
Mei took 10.5 min to travel 3.5 km (distance beyond half way mark).
So when Mei reached the half way mark, Lin would need another 10.5 min to reach the half way mark, i.e Lin was slower than Mei by 10.5 minutes for half the distance.
Hence for the race, Lin would be slower by 2 x 10.5 = 21 min.
21 min past 10.45 a.m. would be 11.06 a.m. (or use timeline)
Lin reach the finishing line at 11.06 a.m.
|
