Probability question (perms and combs) (1 Viewer)

[Michaelmoo]

Ok. Basically heres the question:

Six People, of whom A and B are two, arrange themselves at random in a row. What is the probability that there are at least 3 people between A and B.

Im getting that there is only 3 different positions where A and B can take such that there is AT LEAST three people between the two. A and B can also be arranged amongst themselves in 2! ways. The rest can be arrange in 4! ways. So

P = (3 x 2! x 4!)/ 6! = 1/5

But the answers says 1/2. Any suggestions?

Thanks.

 

[lolokay]

1/5 sounds right to me

 

[Drongoski]

I think 1/5 is right and 1/2 is wrong.

 

[Timothy.Siu]

looks like it

 

[Michaelmoo]

Aahh ok. Thanks then.