Carl Dane was a man who liked calendars. Luckily, he received a small check for his 18th birthday (he was born in April 1975). And guess on what he decided to spend his money? Yes, calendars.
But Carl Dane was kind of frugal: he figured that he could use and reuse a set of calendars until he died, even if he lived to be as old as the oldest man (verified) who ever walked this planet (we're in 1993, remember). Carl Dane did not care about the irregular holidays like Easter; also, he would never write on a calendar. Carl Dane had a calendar for every year since his birth (birth included), but he didn't want to keep the ones he already had that he didn't need. He would just buy the remaining ones that he would need as time went on.
Given that, can you figure out:
- how many calendars he got rid of?
- how many calendars he would need in total?
- how many years it took him to have all the calendars needed?
You'll assume that he doesn't die before completing his collection.