Many candidates were unable to state the uncertainty principle correctly.  Some replaced the inequality sign with equality sign which rendered the equation wrong.
                                                                                                                  -34
At the substitution level,  was wrongly used as    instead of 1.054 x 10-34.  This is as a result of poor interpretation of the question.

Performance was poor.
The expected answer is Let DE = the uncertainty in determining the energy of the electron at the level.
                      DE.  Dt ³  h/2p (the uncertainty principle)
                       OR
                       DE  ³ h/2p  1/Dt
                        ³ 1.054 x 10-37x 1/(2.0 x 10-9)
                        ³   5.27  x  10-28J
NOTE:  Do not accept >,< or  =  in place of >