# Puzzles

Body Title
hollowed out sphere
Resistors 5
Naughts and Crosses
Cylindrical Fuel Tank
liquid in a cylinder
Liquid in a cone
Liquid in a sphere

This is a simple counting exercise; just make sure you don't miss any!

Triangles
Flag Colourings 2

What is the volume of a regular octahedron?

Octahedron Volume

This is the obvious follow up to resistors-2. In this question, you absolutely must use the Kirchhoff laws.

Resistors-3

The natural successor to resistors-1. Some interesting strategies and shortcuts start to appear in this problem. We also need to start thinking in terms of Kirchhoffs laws, if not necessary applying them.

The first law says that at any given node $$\sum I_k = 0$$

The second law says that around any closed loop, $$\sum V_k =0$$

Resistors-2