Through Math for America, I am part of an on-going collaboration with the New York Times Learning Network. My latest contribution, a Test Yourself quiz-question, can be found here:
https://learning.blogs.nytimes.com/2012/01/23/test-yourself-math-jan-23-2012/
This question is related to a publicly-funded program that trains private-sector employees in North Carolina. Just how much does this program cost the government?
Today we celebrate our first Permutation Day of the new year! I call days like today permutation days because the digits of the day and month can be rearranged to form the year.
We enjoyed several Permutation Days in 2011. In addition to predicting future dates, an interesting question would be “Which year has the most Permutation Days?”
In honor of today, I recommend changing the order in which you do things!
Parabolas and fountains definitely seem to go together.
And check out these water parabolas at the Detroit Airport!
This is a short and engaging little vocabulary quiz from www.sporcle.com titled “F in Math”.
http://www.sporcle.com/games/puckett86/dont_fail
To paraphrase Alex Trebek: all the answers in this quiz begin with the letter F.
If you don’t get a 100, don’t feel bad; one of these answers is a bit obscure. I got it right, but only because a student recently explained that particular concept with me . I didn’t really understand, but at least I remembered the word!
This is a nice introductory video on elementary queuing theory from Bill Hammack, the engineer guy.
http://www.youtube.com/watch?v=F5Ri_HhziI0
Hammack poses a classic queuing theory conundrum: people in a town use phone lines at an average rate of two per hour; how many phone lines should the town have? The naive answer of two lines is far from optimal, because of bunching.
In addition to exploring this basic idea, Hammack also discusses the efficiency of the single-line system (everyone waits in one line for the next available cashier) versus the multiple-line system (each cashier has a separate line). Assuming that delays are distributed randomly among the cashiers, the single-line system minimizes the overall impact of a delay at any one cashier, and so, is more efficient.
And if every individual line has an equal chance of experiencing a delay, it stands to reason that every line has an equal chance of being the fastest. This explains why the other line always seems to move faster: if there are ten lines, you’ve got a 1 in 10 chance of choosing the fastest one, which means 9 times out of 10 a different line is moving faster!