For Problem 20, what multiple of h2/8mL2 gives the energy of? (a) The first excited state, (b)

Question:

For Problem 20, what multiple of h2/8mL2 gives the energy of?
(a) The first excited state,
(b) The second excited state,
(c) The third excited state of the system of seven electrons?
(d) Construct an energy-level diagram for the lowest four energy levels.