A fair die is successively rolled. Let X and Y denote, respectively, the number of rolls necessary to obtain a 6 and a 5

[answerhappygod]

A fair die is successively rolled. Let X and Y denote,
respectively, the number of rolls necessary to obtain a 6 and a 5.
Find
(a) E[X]
(b) E[X | Y = 1]
(c) E[X | Y = 5]
Hint: This one is tricky. Use intuition rather than formal
calculations with PDFs. Break into the cases X <5 and X
>5.