These secondary problems have not yet been solved. Can you be the first?

Using only the red and white rods, how many different ways are there to make up the other rods?

Can you make lines of Cuisenaire rods that differ by 1?

Pick two rods of different colours. Given an unlimited supply of rods of each of the two colours, how can we work out what fraction the shorter rod is of the longer one?

If you have a large supply of 3kg and 8kg weights, how many of each would you need for the average (mean) of the weights to be 6kg?

How many different lengths is it possible to measure with a set of three rods?