! three), or blue (length four).
! If red tiles are chosen there are exactly seven ways this can be done.
! If green tiles are chosen there are three ways.
! And if blue tiles are chosen there are two ways.
! three), or blue (length four).
! If red tiles are chosen there are exactly seven ways this can be done.
! If green tiles are chosen there are three ways.
! And if blue tiles are chosen there are two ways.