Discussion :: Races and Games - General Questions (Q.No.2)
|Naresh.Ravula said: (Dec 21, 2010)|
|While finding the speed of the B, why we are using the 92m only instead of 100m?|
|Sanju said: (May 15, 2011)|
|Out of 100m he ran 8m so we deduct 8m from 100m then we get 92m to obtain B Speed we should caluclate B Speed by using 92m instead of 100m. I hope you understand. !|
|Rajesh said: (Sep 18, 2011)|
|We should understand the ques properly. Its in the ques that b is 8m forward than a in 100m race, am I right?|
|Padma said: (Sep 24, 2011)|
|Here first we can find the losers time, secondly we can find losers distance[since losers distance=winners distance- (start distance+beat distance) ] and later we can find the speed of B[since speed=distance/time]. Which is the final answer.
Is this not the correct procedure. Please tell me if it is.
|Baburaj said: (Dec 16, 2011)|
|Why Time taken by B to cover 92 m = (72 + 8) = 80 sec. comes?
Can any one explain ?
|Sudharshan Madgula said: (Jan 16, 2012)|
Because A is taking 72sec to run 100m and beats B by 8sec.
that means still B needs 8sec to complete 100m.
therefore time taken by B to complete 92m is 72+8=80sec.
|Anamika Sinha said: (Jan 21, 2012)|
|How did you get A's speed ? I dint understand. Please explain.|
|Sayed said: (Jan 21, 2012)|
|How A's speed is found ?|
|Jaanvi said: (Jan 23, 2012)|
|@anamika & sayed
A's speed is in kmph. to make it in m/s, 5 is multiplied with 1000/(60X60).
|Sag said: (Aug 25, 2012)|
|We are adding 8 second to cmplete 100m for b. So why his speed is calulated for 92 m. It should be for 100m and answer should be 4. 25.|
|Mangesh said: (Sep 18, 2012)|
|Since both are covering 100m finally. So why we took 92m instead 100m ?|
|Qwaci said: (Nov 22, 2012)|
|@ Sag & Mangesh.
First of all, A gave B a start of 8m so B did not run 100m but 92m (100m-8m). Secondly, A took 72sec to cover the 100m and still won B who had only 92m to run by 8sec which means that with the 92m that B covered he used or needed 80sec (72sec+8sec). I hope my little explanation could help you understand.
|Prafull Gadekar said: (Jun 24, 2013)|
|Instead of taking 5/18, we solve like,
A 's speed = 5 kmph = 5000 mph = 5000/3600 = 1.38m/sec,
For 100m distance time = 72.3 sec or 72 sec,
B's require time to cover 92m distance=(72+8) = 80 sec.
80 sec- 92m then,
1 sec - 1.15m.
1.15*3600 = 4140 mph = 4.14 kmph.
|Girijesh said: (Aug 4, 2013)|
|Let speed of B is x meter/sec.
Speed of A is y meter/sec.
Total time to reach 100 meter by A is 100m/5kmph = 72 sec.
Total time to reach 100 meter by B is:
(8/x) + time taken by A + 8 = 100/x.
(8/x) + 72 + 8 = 100/x.
x = 92/80 m/s = 4.14 kmph.
|Prasanna said: (Aug 30, 2013)|
|Why can't we change the distance into km and solve?. I am not getting the answer in that way.|
|Buddhika said: (Dec 30, 2014)|
|Forget 5 kmh.
A runs = 8 m.
B runs = 100-8 = 92 m.
B speed = 92 m/8 s = 11.5 ms.
Now we convert ms = kmh.
11.5 x 18/5 = 4.14 kmh.
That is all.
|Deepali said: (May 26, 2015)|
|How get 18?|
|Vinay said: (Sep 25, 2015)|
|We have given speed of A = 5 km/h => 5x5/18 = (25/18) speed;
A takes time = 100x (18/25), Time = Distance/Speed;
Since A beat B by 8 sec.
So total time taken by B = 72+8 = 80 (time);
Since A gives 8 m to B.
So total distance cover by B = 100-8 = 92 (dist);
We know that Speed = Distance/Time;
Now speed of B = 92/80 m/s;
Now converting it into km/h => (92/80) x (18/5).
=> 4.4 answer.
|Manisha said: (May 26, 2016)|
|I can't understand why we have to use 18/5, where it come from? Can anyone explain?|
|Sravs said: (Jun 22, 2016)|
|18/5 is the conversion of m/s to km/hr. Because option is in km/hr. We need to convert.|
|Ashutosh Kumar said: (Sep 2, 2016)|
|A --> 100m.
B --> 92m.
Above is the situation B covers 92m in 72 + 8 = 80s therefore we have taken 92m to calculate the speed of B.
|Mariyappa said: (Mar 24, 2017)|
|How get 18 came here?|
|Sairam said: (Mar 4, 2019)|
|Actually, B has to complete 92 meters in 72 seconds but he is taking an extra 8 seconds time to complete 100 meters which can be concluded from the question. Am I right?|
|Sileshi said: (May 23, 2019)|
|How come 5/18? Please tell me.|
|Rocktim said: (Jul 5, 2019)|
|How come 5/18? Please tell me.|
|Manikanta said: (Aug 12, 2019)|
|Here A runs for 100meters while B has to run only for 92Meters as B is 8meters ahead of A.
5km per hour=5000 meters per hour.
As the question is asking in seconds. Now convert for each second how many meters A is running.
Here we have 3600 seconds for one hour.
So 5000meters or 5*1000meters/3600 which comes to 5*5/18=25/18.
In how many seconds A ran the100meters =100m*25/18sec=72sec.
A has run 8seconds faster than B. Which means B took 8seconds more to complete the run. Therefore 72+8=80Sec.
Now the question is B's speed in km per hour.
Calculate for each sec how many meters he ran=92meters/80sec.
Hence=92/80*18/5 (lets say 3600sec/1000meters) =4.14kmph.
|Anusha said: (Jun 18, 2020)|
|Nice explanation, thanks @Buddhika.|
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