Discussion :: Races and Games - General Questions (Q.No.3)
|Kriti said: (Dec 3, 2010)|
|Hi, when 3:4 is the ratio of speeds how can we use it
as 3m and 4m for A and B resp.?
|Sudheer said: (May 19, 2011)|
|Hi kriti here speed and distance are directly proportinal. If his speed is 10km/hr he cover 10km distance. If speed is 20km/hr he can cover 20 km distance. Thus speed and distance are directly proportinal. So here distance ratios also become3:4. But the time ratio will become4:3 because time and speed are inversly proportinal.|
|Vamsi said: (Jul 5, 2011)|
|I didn't understand how it can be 4/3. ?|
|Malli said: (Sep 30, 2011)|
|Hai, my dout is same that of vamsi.
Why we had taken 4/3 in problem?
|Manojit said: (Feb 9, 2012)|
|While A covers 3 m, B covers 4 m.
While A covers 1m, B covers 4/3 m.
While A covers 360 m, B covers (4/3* 360)m =480 m.
Here time is same in case of speed.we count different distance in same time.
|Rajesh said: (Feb 7, 2013)|
|Can be solved by simple calculation.
A covers 360m (ie) 500-140.
Ratio of speeds of A:B = 3:4.
Let us consider A covers 3m/sec & B covers 4m/sec.
Time taken by A to cover 360m=(360/3)=120seconds.
So,Distance covered by B in 120s =120*4=480m.
Therefore,A wins by 20 metres which is (500-480).
|Srinu said: (Feb 8, 2015)|
|Time = dis\speed.
T = 360\3 = 120sec.
Now dis = sxT = 4x120 = 480m.
So 500-480 = 20m.
This is the answer.
|Newstein Faraday . said: (Jul 1, 2015)|
|A has to travel 360 meters therefore Time =distance/ speed. So 360/3 = 120 seconds.
The same 120 seconds b has to travel so distance = speed x time = 4 x 120 = 480.
The remaining distance that b has to travel is 500-480 = 20.
|Damini.arora said: (Aug 25, 2015)|
|Here, because A has a start of 140, he has already covered 140 m when B starts. So when A covers rest of 360, B covers 480.
Hence B loses race by 20 m.
|Ash said: (Jan 19, 2016)|
|Speed is directly proportional to distance.
3/4 = (500-140)/(500-x).
3/4 = 360/(500-x).
Hence x = 20.
|Anand said: (Sep 1, 2019)|
|Here is the simplest method,
Speed ratio is 3:4 SO let consider 3m & 4m for both A & B.
A travels 360 and B travels 500.
This means A takes 120 seconds and B takes 125 seconds.
5 seconds more than A is travelled by B.
In one B travels 4m.
So in 5 seconds, 5*4=20m.
B travels 20m more than A.
That is A win by 20m.
|BKD said: (Dec 1, 2020)|
|3/4 = (500-140)/x.
x = 480.
Thus, In 500 m race, A gives B by 20m i.e.500-480.
|ANUPCHERRY said: (Jun 29, 2021)|
|A : B =140M.
3X + 4X =7X,
140/7 = 20M.
|Yadu said: (May 26, 2022)|
|How come we take 3 as 3m and 4 as 4m If time is not a constant here?
Anyone, explain to me.
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