You have n items, with probability of .05, .1, .3 ..p(n).. = 1 = 100%
How can you calculate the expected amount of tries to get all items since they have unequal probability?
Then how can you calculate the expected amount of tries once you take out an item after it's been received x times?
In other words, once you get an item x times, it's probability changes to 0 causing all other items to shift accordingly.
If you have three items, .25 .25 .50. Then take out the .50 item, your chances of getting one of the last two items becomes .50 and .50.