You have 330 boxes each requiring a key. 15 keys can be bought for 300 gems a day. If your total boxes increase by 5 a day, how many gems will have to be spent, and how many days will have passed?
It's nothing serious. Just a question I came up with for a game I'm playing. I'm always getting these boxes in it, and I want to know how many gems would have to be spent for every box I have and will get, and how long it would take to open them all.