How to set the priority of objects from a collection? GN

[fase169 (Ivan Orlov)]

How can I create, let’s say, a ratio of objects from a collection?
There is such a function when working with particles, but what about in GN?

[DNorman]

The instance index lets you choose index numbers.
You can do different math to vary the input.
For example;

The monkey and icosphere have the indexes 3 and 4 I set the probability of selecting them low so there are many more cylinders cubes and cones (0, 1 and 2 ).