Probability problem, very hard

[alexis866]

aaaa

 

[HallsofIvy]

Have you done problem 1? Problem 2 says "This one may seem easy/trivial if you have completed problem 1, since it is looking at the same problem in just a slightly different way."
Look back at how you did problem 1 and see if you can tell how it applies.

 

[alexis866]

hi

i don't know. really i tried and tried . can't seem to find a right answer or to resolve it.

 

[alexis866]

you can delete the post if u want to. i resolve the problem and thanks u for everything