I recently started playing a rhythm game that also has gacha elements. Think piano tiles but harder.


    Gacha games always have a tier system with higher tier units being harder to pull. The game in question has a pull rate of 3% for their rarest unit tier, tier 4 (which is actually really good).


    In total I have pulled 61 times so far, 7 of which has been 4 star units, definitely all due to "luck." This is a fantastic example of a situation which you can use to practice probability calculations.


    (Tip: The order in which units are pulled is irrelevant so you''ll need to account for all possible combinations)


    [The game was released recently and is called Hatsume Miku Colorful Stage for anyone interested]