Wednesday, December 11, 2013

Purple Argyle Sweater Day: A Story Problem

So, what are the chances that three teachers in the same school actually own V-neck argyle sweaters with a pattern in some shade of purple?
And how likely is it that all three of them will be English teachers?
And what, exactly, is the probability that all three of them will accidentally wear their purple argyle sweaters on the same day?

Round your answer to the nearest tenth.


  1. Well. maybe it's just me, but argyle sweaters and English teachers seem to go together, so I'll set the probability of them all owning one at .67 (2 out of 3). V-neck versus regular neck would be 1 out of two, so .5. There are 180 days in a school year, so for two of them to wear them on the same day would be 1 our of 180, or .006. Once the other two have shown up wearing V-neck argyle sweaters, it would still be 1 out of 180 that the third one would also be wearing one. So, the probability that three English teachers would wear a V-neck argyle sweaters on the same day would be .67*.5*.5*.5*.006*.006 or 0.000003015 or about 3 in a million.

  2. This is why English teachers have math teacher friends: they do the math. :)

  3. And the sick thing is - I enjoyed figuring it out.

  4. So funny! I am an English teacher who doesn't own an argyle sweater - a non-conformist, obviously :D