Question

A person needs to find the fastest two horses from 16 horses. Only a race of 4 horses can be conducted at a time. What is the minimum number of races to be conducted to determine the fastest two? (Assume that horses will not get tired at all and time cannot be measured)

• A. 6
• B. 7
• C. 8
• D. 16

Hint:

In such problems, break the task into groups and use elimination or qualification strategies to reduce the number of options.

Answer 1

The Correct Option is B

To determine the fastest two horses, the approach involves conducting 5 races to sort the horses into groups of 4. After that, the top 2 horses of each group race against each other: - 1st race: 4 horses - 2nd race: 4 horses - 3rd race: 4 horses - 4th race: 4 horses - 5th race: 4 horses Then, take the winners from each group and have a final race (6th race) with the winners. The top 2 from this race are the fastest.