JUST A PUZZLE. Can anyone explain with the answer?

Question

There are 25 horses among which you need to find out the fastest 3 horses. You can conduct race among at most 5 to find out their relative speed. At no point you can find out the actual speed of the horse in a race. Find out how many races are required to get the top 3 horses.

Answer 1

yup....... seven is correct
https://youtu.be/i-xqRDwpilM

Answer 2

Fun-fact: That's a google interview question.

Answer 3

7 or 8?

Answer 4

@farshaad yes, got it right. it's 7. but i want to know how..... please help, anyone?

Answer 5

@nishant no, the answer is 7. i don't know how, but answer is 7

Answer 6

i just roughly thought about it but .....
you make a first race between five horses
then you take the winner and put it in another race with 4 new horses. and so on till u have raced all horses then make a race between last three winner's

again. I didn't think about it deeply.. but it should give u an idea of finding the answer

Answer 7

yes the right answer is 7

https://www.geeksforgeeks.org/puzzle-9-find-the-fastest-3-horses/

Answer 8

@alex : fastest horse gets in the next race
@nishant:. logicly if we have a stopwatch. it wouldn't be a puzzle at all......

Answer 9

@nishant no, it's not five....

Answer 10

hint: the 2nd fastest horse of the fastest group may be faster than the fastest horse of the 2nd fastest group @farshaad

Answer 11

"at no point you can find out the actual speed of the horse in a race"