### Upsetting Pitagoras

Find the smallest integer solution to the equation 1/x^2 + 1/y^2 = 1/z^2

### Lunar Leaper

Gravity on the Moon is about 1/6th that on the Earth. A pole-vaulter 2 metres tall can clear a 5 metres pole on the Earth. How high a pole could he clear on the Moon?

### Seriesly

Prove that k.k! = (k+1)! - k! and sum the series 1.1! + 2.2! + 3.3! +...+n.n!

# Odd One Out

##### Stage: 5 Short Challenge Level:

Some of the odd ones out may be easier to spot than others.

You might first like to generate lots of sets of the random numbers so that you can get a feel for the the patterns in the randomness.

Start off by looking to see what sorts of things the numbers have in common and how they may logically be generated. Once you have a logical method of generation (which is only a guess, of course) you can check to see whether all but one of the numbers fits that method of generation. If you think that you have found an explanation, consider the likelihood of numbers generated by some other method accidentally fitting your pattern.