Electron confined in a one dimensional box

[tboyers]

Homework Statement

An electron confined in a one-dimensional box is observed, at different times, to have energies of 27 eV , 48 eV , and 75 eV .
What is the length of the box? Hint: Assume that the quantum numbers of these energy levels are less than 10.

Homework Equations

E=h^2n^2/(8mL^2)

The Attempt at a Solution

I tried using that equation to solve for length, but I don't know what energy levels these are at, so i can't seem to solve it.

 

[drvrm]

I tried using that equation to solve for length, but I don't know what energy levels these are at, so i can't seem to solve it.

energy of the states are proportional to n^2/L^2 and you have energies for three states so can you find out L?