Question

A guy walks in the store and steals 100 without the owners knowledge. He comes back 5 minutes later and buys 70 dollars worth of goods with the 100 dollar bill. The owner gives him back 30 in change

Answer 1

Assuming the question is how much did he lose, it's $100. If we assume he started with $500 in his register, the original $100 stolen lowers it down to $400. The guy buying $70 worth of stuff puts it back to $470 in the register, but now with $70 less merchandise, so he lost $30 in cash and $70 in merchandise.