Nupur came to mayank's house, it is not bushan house... if you people remember in some sbb segment arjun said "cheque mara account se jathe the" - taking this as point i think mayank did charity and taken care of some patients in hospital, and nupur is one of them.. so as nupur missed her bus she want to go to that person who helped her and say thanks to him before moving to delhi.. so she took mayank house address and came to his house and she will be suprised to see mayank there.....
I think nupur lost her memory..