How to complete the Tower of London test

In this task you need to work out the number of “moves” it would take to change the top image into the bottom image. A move is taking one tile from the top of a pile and moving it to any other peg.

So, if you had a top image that had a blue tile on the left peg and a red tile on the right peg, then a bottom image with a blue tile and then a red tile on the left peg, the answer to the question would be 1 as you only need to make 1 move (the red tile from the right peg to the left peg).