Math

If a 5 star character drop rate is 0.80000% and the average drop rate (inculding guarantee) is 1.80000%. theres a guaranteed 5 star every 80 pulls. Every 5 star obtained if a 50% chance of a featured 5 star and 50% chance to be a random 5 star. If the 5 star obtain is not a featured character the next 5 star will be a guaranteed featured 5 star. (Also applied to weapon banner)

I have a guranteed pull on my next 5 star. I have save 35 pulls for the next featured character. What are the rate of me getting limited 5 star and how many more should i save?

(This is stupid )