Mars Cashier interview questions

I was called few hours after i gave my application and resume. They asked me if i could come for an interview the same day and i accepted. I met the manager in the area i wanted to work (Cashier) and she asked me lot of questions about me, my motivation, the store, and then i did a drug test. I waited to see after the drug test if they will offer me the job or not, i had nothing to worry about this test, i don t smoke or use any kind of drugs so ... and when they came back they asked me when i could start to work, and if i will be interested to work part time, i asked if i would have the opportunity or not to become a full time and the answer was yest probably in a couple of months because one of the lady was retiring and will depend on how good i work