Oh, how will I top my last post?
Actually I discovered James Tanton who tweets interesting math questions. I’m not sure how he always gets them in in 140 characters, but somehow it works. I spent an hour twice working on two puzzles.
Here is one: 2/5 = 26/65 = 266/665 = 2666/6665 = …. Other examples? I actually got this from @republicofmath who had added a few solutions. I was able to show that @republicofmath had all the solutions.
Here is another: “36” is both square and triangular. (36 = 6×6 and 36=1+2+3+..+7+8). What’s the next squangular number? (And the next?) For this one I learned about some number theory I had not discovered before. It involves some algebra to rearrange this as Pell’s equation.
At any rate if you like math puzzles and you have the self control to limit yourself to a couple problems a week it might be fun to follow @jamestanton or visit http://twitter.com/jamestanton every once in awhile.