Originally Posted by

**tomdoml** Just having a bit of a problem with a particular permutation question.

Q - Four girls (Anne, Pela, Jeanette and Philippa) and three boys (Tony , Jason, and Bill) arrange themselves in a line at the checkout. If the arrangements are random, find the probability that Anne and Pela will be served before tony

My attempt.

5 possible situations, two girls always on the right side of the line, tony always on the left side of the line.

x x x x x | x x permutations 5P5 * 2!

x x x x | x x x permutations 5P4 * 3!

x x x | x x x x permutations 5P3 * 4!

x x | x x x x x permutations 5P2 * 5!

x | x x x x x x permutations 5P1 * 6!

add them up and put it over 7! and it comes out as 5/3 obviously wrong lol :S.