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The Riddler - Series on FiveThirtyEight
#6
RE: The Riddler - Series on FiveThirtyEight
The Riddler PUZZLE TWO - Which Geyser Gushes First?

This is the 2nd puzzle in FiveThirtyEight's The Riddler series, in which Oliver Roeder posts an interesting math/creative thinking-ish brain-teaser every Friday.  I'll post either my solution (if I can come up with one) or my initial thoughts (if I don't see how to solve it) in hide tags, and everyone is welcome to give it a go! I have promised a rep to people who solve a problem that I got wrong Big Grin

The first Riddler question (see above) lulled me into a false sense of security, and I got it hella wrong.  So, here's number two:


Quote:Now, here’s this week’s Riddler, which comes to us from Brian Galebach, an amateur mathematician from Columbia, Maryland:


You arrive at the beautiful Three Geysers National Park. You read a placard explaining that the three eponymous geysers — creatively named A, B and C — erupt at intervals of precisely two hours, four hours and six hours, respectively. However, you just got there, so you have no idea how the three eruptions are staggered. Assuming they each started erupting at some independently random point in history, what are the probabilities that A, B and C, respectively, will be the first to erupt after your arrival?

This was the first Riddler question I read, and I saw how to solve it straight away (it just took a little bit to work out the numbers).  Here's my groundwork - my initial way of thinking about the problem - which you can check out if you want a hint:




And then here's the solution:




That one was a bit easier if you're not afraid of fractions Big Grin I haven't looked at any of the remaining problems, so I'll be working through them on here over the coming days!  POST YOUR SOLUTIONS AND SHOW ME HOW AWESOME YOU ARE.

Joe's Record through 2 Riddler Puzzles: 1-1
How will we know, when the morning comes, we are still human? - 2D

Don't worry, my friend.  If this be the end, then so shall it be.
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Messages In This Thread
The Riddler - Series on FiveThirtyEight - by TheRealJoeFish - February 24, 2016 at 3:29 pm
RE: The Riddler - Series on FiveThirtyEight - by ignoramus - February 25, 2016 at 5:06 am
RE: The Riddler - Series on FiveThirtyEight - by TheRealJoeFish - February 25, 2016 at 11:13 am
RE: The Riddler - Series on FiveThirtyEight - by Kitty Galore - February 25, 2016 at 11:26 am
RE: The Riddler - Series on FiveThirtyEight - by TheRealJoeFish - February 25, 2016 at 4:11 pm

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