Euler found four whole numbers such that the sum of any two of the numbers is a perfect square...
The diagram illustrates the formula: 1 + 3 + 5 + ... + (2n - 1) = n² Use the diagram to show that any odd number is the difference of two squares.
Find the frequency distribution for ordinary English, and use it to help you crack the code.
A plastic funnel is used to pour liquids through narrow apertures.
Have you ever tried pouring a drink from a glass back into a bottle ?
You don't need a specified volume, but it may help to ask what proportion cone would hold a litre of liquid using the least amount of plastic.
See the Hint for more help.