1) In S6 find 12 permutations that commute with alpha=(1,2,4,5)
i did (5,1,2,4)
(4,5,1,2)
(2,4,5,1)
?i don't know if transposition answers this?
but i also did
(1,5)(1,4)(1,2)
and similar for the ones above
i also used
(1,2,4,5)(2,1)
(1,2,4,5)(4,5)...