Given 91 horses,
a> find the best 4 horses with minimum number of races. Each race can have only 9 horses. You don't have a timer.
b> find the minimum races by which we know that one horse surely in top four?

• a & b both have the same answer I.e. 10...
• 11 years agoHelpfull: Yes(3) No(1)
• Ans a.)min 18 races
  b.)min 18 races18
  explanation:-
  we dont know dat 4 best horses are in a single group of 9 or in different. So we will carry out race b/w 9 horses and filter out 5 of them,the remaining 4 best horses are again included in the next group like this way:
  initially,91,(91-5),(91-5-5) and so on....
  So to filter out best of all 90 horses, we have to carry out race for at least 91/5=18 remainder 1(best horse).
• 11 years agoHelpfull: Yes(3) No(2)
• a-18
  b-11. i think this is correct
• 11 years agoHelpfull: Yes(1) No(1)
• there is amistake that there are 81 horses instead of 91
• 11 years agoHelpfull: Yes(1) No(1)