Elastic recovery

Razor

Hello all Im doing material science and I can understand most questions except this one,

"A 10mm – diameter bar of Medium carbon steel (E=200GPa) subjected to a tensile load of 50KN, taking it beyond its yield point. Calculate the elastic recovery that would occur upon removal of tensile load. "

I have seen a question like this in the earlier forum psts but in that case they were given the yield stress and the length of the bar. Any help will be much appreciated.