Happy New Year!
Here’s a little brainteaser to get us off to a good start for 2013:
You have 5 sticks of lengths 1, 2, 3, 4, and 5 inches. If you choose 3 of them at random, what’s the likelihood that the 3 sticks can be put together, tip to tip, to form a triangle?
SOLUTION to the Cryptoquote of December 4:
One of the most glorious messes in the world is the mess created in the living room on Christmas day. Don’t clean it up too quickly. ~Andy Rooney
(But, with any luck, by now you have your living room back to “normal!”)
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Math Puzzle .
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Can’t any 3 sticks – as long as they’re different lengths – form a triangle of some sort? I must be missing something (not a rare event for me where math’s considered).
a guess – I’m sure there are formulas I no longer remember!
I say 3/10 because I think there are 10 combinations and only 3 could form a triangle (234,245,345)
Mary, I’m not surprised you got it! A prize is on the way for being first!
Susan, it’s the “tip to tip” that makes it different; i.e., not just 3 sticks crossing and intersecting at any point. Clear? Thanks for participating; I’ll try to make the problem more clear next time!
I was going to agree with Susan, but now I see the error of my ways. If it helps Susan, think about sticks of length 1, 2, and 5 inches. The farthest the tips of the 1&2 sticks can be is 3 inches (if they’re laying end to end), so can’t form a triangle with 4″ and 5″ sticks. I guess Camille doesn’t consider a “triangle” of 1, 2, and 3″ as being a true triangle, as it would be a straight line with 3 sides. How confusing is that?
Yup – Now I see, said the blind woman!