##### Click the image to link to GeoGebraTube

(Opens in a new window/tab).

.

This applet is for visualising the Binomial Distribution, with control over n and p.

It also shows the Normal Approximation curve (and how this approximation breaks down for large or small p)

and it shows the Poisson Approximation curve (and how his approximation breaks down if there’s no positive skew)

You can show critical regions at either end by turning the bars red instead of green. The appropriate cumulative binomial probabilities are shown.

February 19th, 2010
Micky

### Problem:

When the area of the green square is *two-fifths* of the area of the whole diagram, w*hat fraction do the four black triangles occupy*?

**Open the post to play with a Java applet.**

Read more…

September 27th, 2009
Micky
### A Geometric Secret of A4 Paper

## Problem:

We wish to make **two** folds in a rectangular piece of paper to form a trapezium (or trapezoid for the chaps across the water). Read more…

September 13th, 2009
Micky

In Part I we calculated the probability of winning a single-suit version of the Higher of Lower card game. **The objective of this post is to find the probability of winning the full, unsimplified, 4-suit version of the game** played in pubs across the land. Read more…

September 5th, 2009
Micky

I was recently roped into joining some friends for a pub quiz. I hate pub quizzes. For a start, I don’t watch soaps or football or take any interest in divorcing celebrities. The sum total of my contribution is usually a question about the periodic table and another about some obscure ’90’s one-hit wonder.

At the end of this particular quiz there was a competition to win a pot of dosh. Those optimistic enough to enter first had to be lucky enough to have their number drawn from a hat, and then attempt to win the ominous game of Higher or Lower, or “Play Your Cards Right” as it is sometimes known, via a crudely written flash program running on the host’s laptop. If you win the game, you win the cash. Easy? Apparently not. Two players failed in succession and then the host declared that the contents of the pot would roll over to next week. Almost everyone in the pub had just lost a quid. Would anyone ever win the money? I didn’t know, but I was alarmed and **it was my duty to discover the probability of winning this game**.

### A Geometric Secret of A4 Paper

I’m not just going to give the answer away this time! At least not for a while anyway… (**Click here for the solution**) Read more…

### Visualising imaginary forms…

This post builds further on the concepts discussed in the original 1-in-10 Gay Problem post and its sequel, Find a way to my Heart, and delves **deeper into the abstract** to discover an impressive 3d form hidden in our function. It will be assumed that the reader has studied these preceding posts (10 minutes’ fascinating reading!) Read more…

This post builds on the ideas from the first 1-in-10 Gay Problem post and takes a step into the creative world of **abstract maths**.

Read more…

**…a maths problem that is.**

**“If 1-in-10 people are gay, and there are 10 people in a room, one of the people in the room must be gay!”**

Is this true? Take a look here for the full analysis!

Read more…