Question

ONLY ANSWER IF YOU HAVE SOLUTION OR ELSE U WILL BE REPORTED!

There are 12 runners in marathon and all runners have equal chance of winning. What is the probability that a person may win a bet on the race if he has to correctly select the top 3 runners and
the order they finish in?
a) 1/1320 b) 1/1728
c) 3/1728 d) 1/12
kindly solve it using permutation technique

Answer 1

A) 1/1320

Explanation:

We know there are 12 runners in the race. Of these 12 people, one of them will get first place. In other words, 12 people have a chance of getting first place. Now there are 11 people remaining to get second place. Since one of the twelfth came first place, there are now 11 runners remaining to get second place. Finally, there are 10 people remaining. Since two of the 12 people came first and second, there are 10 people remaining who can get third place. So if a person was to correctly select the top 3 runners, then he would have a chance of 1/1320. You get this by multiplying 10, 11,12. You get 1320. since you have to pick one combination of 1st,2nd, and 3rd, the answer is A.