Around 99% - 100%. This is because a die is six sided, which gives the odds of a one coming up being roughly 17% independent of every roll. 17% of 180 trials comes out to 30-31 times a one will show up every 180 trials. This puts you right in the middle of the 15-45 range which means that somebody will almost ALWAYS reach 15-45 one's in a trial of 180 rolls.
