For the third, fourth, fifth, and sixth levels of the three-dimensional cubical box, find the energies in terms of the quantity E0= π^2*hbar^2/(2mL^2), where m is the particle mass and L is the box's sidelength. _____E0 (third level) _____E0 (fourth level) _____E0 (fifth level) _____E0 (sixth level) Which, if any, are degenerate? So the equation that I am using is E=E0*(n1^2+n2^2+n3^2), where n1, n2, n3 are energy levels. For third level, I used n1=1, n2=n3=2, so I got 9*E0. I thought that for 4th level I would just raise one level, making n1=n2=n3=2, and get 12*E0, but this doesn't work. Can anyone give me a hint as to what I'm doing wrong? Also, the third level will be degenerate, correct?