How to calculate when will I have certain amount of ITEMS based on drop rate

[metal.stuff]

Hello all,
in column A, I have 6 items with drop chances. But, a drop drops 3 items, based on their percentage.
In cell B, I have how many items I need.
I want in cell C to calculate, how many tries its going to take me to get an X amount of item 1 for example.

To provide an example:
Item 1 has a drop chance of 16%. A single drop drops 3 items however (Item 1-Item5, based on percentage)
I need 5 items 1.
How many tries is it statistically going to take me to get the 5 items 1?

Cheers