# PROBLEM 21 # 
Standard formula used 
 E = (n^2 * h^2) / (8 * m * L^2)) 

 Energy Eigen values -
 For (n=2) for 80.000000 eV.
 For (n=3) is 180.000000 eV.
 For (n=4) is 320.000000 eV.