Its simple 2 EM on 100 spent in multiple of 100s, so for 79 you will get nothing, for 151 you will get 2 EM, same as 179, 2 EM and lastly for 226 you will get 4 EM. Now again this is base EM, it depends upon where you have spent these. So if they are in the forbidden category then 0 EM also possible