Here is a link to the problem I'm talking about. Does anybody know how to solve this? https://www.newyearofpuzzles.com/teaser
Decided to post on CF because there are lots of smart people here. This is my idea right now:
Solution idea
The hint says you don't need a calculator but the only solution I can come up with would need a calculator. Unless there is some way to do these combinatorics in your head.
