Are you Logical enough .......???
Logic
Level
3
Manikant has 25 horses, and he wants to pick the fastest 3 horses out of those 25. He has only 5 tracks that means only 5 horses can run at a time and he doesn’t have a stop watch. What is the minimum number of races required to find the 3 fastest horses?
The answer is 7.
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1 solution
First, divide 25 horses into 5 groups. There would be five races for this 5 groups.List the first three horses from each of the 5 groups. For example;
Now, There should be one race between the 5 topper horses. So after that, we know which one is the fastest horse. Let's assume, the result of the 6th race is like the following:
So now we have to settle the 2nd and 3rd place.This is the tricky part. Think a bit, in our assumed case above,who should be the possible 2nd placers ? Of course the 2nd of the 6th race or the 2nd of the primary race of Group 2 ( as the others are always at least 2 positions behind from the top horse, so they can never be the 2nd fastest horse). And who should be the third placers? If you think a bit, you will find that, 3rd horse from the 6th race or 3rd horse from the primary race of Group 2 or the 2nd horse from the primary race of Group 5, these three are candidates for the actual 3rd place. So there should happen a 7th race among these 5 candidates for 2nd and 3rd places.The top two horse of this race will be the final 2nd and 3rd fastest horse.
So the minimal number of races is 7.