It’s easier to work out the probability you *don’t* get it, then subtract that probability from 1.

Probability you don’t get it once:

9/10

Probability you don’t get it the first time or the second time:

9/10 * 9/10 = (9/10)^2

Probability you don’t get it every single time:

(9/10)^5

Probability you do get it at least once:

1 - (9/10)^5

Plug that into a calculator and you get 0.40951, so just over 40% or 4/10.