Aguy walks into a store and steals $100 from register, comes back and buys $70 worth of merchandise, pys for it with same $100 and gets $30 cash back. how much did store lose?

In order to know the answer for this one, let us analyze the whole problem.
Given that the store already lose $100 stolen by the guy, this guy also bought a merchandise worth 70$, and gets a change of $30. The merchandise was paid, but still, the store lost $100, and then an additional $30, for giving it back to the guy. So the total lost of the store would be $130. Hope this answer helps.

C. i think it is step 3