Archives for math

The two envelope paradox

I’m a sucker for probability puzzles. Here’s an interesting and unusual one I found on the site of Amos Storkey: You are taking part in a game show. The host introduces you to two envelopes. He explains carefully that you will get to choose one of the envelopes, and keep the money that it contains. […]

Too lazy to flip coins

I was helping my daughter with some math homework; one of the problems was to flip three coins and tabulate the number of heads over the course of eighty trials. This struck me as excessively tedious, so I suggested we write a computer simulation instead. Here it is, in its full glory: coin := Random[Integer, […]

Euler 100

Euler Project problems can be addictive. This one gave me fits. If a box contains twenty-one coloured discs, composed of fifteen blue discs and six red discs, and two discs were taken at random, it can be seen that the probability of taking two blue discs, P(BB) = (15/21)×(14/20) = 1/2. The next such arrangement, […]

Euler 183

I have not worked a Euler Project problem in some time. Here’s problem 183: Let N be a positive integer and let N be split into k equal parts, r = N/k, so that N = r + r + … + r. Let P be the product of these parts, P = r × […]

math resources

In my fantasy life, the one where I have some spare time and am not bleary from lack of sleep, I imagine myself studying math. Really. Here’s a nice list of free online math books.