Someone came into my shop and stole $100 out of the register without my knowledge. The person came with the same $100 5 minutes later and he bought $70 in Items and I gave him back $30 change. How much money did I loose!!!!!!

Respuesta :

You had 100. you then had 0. You then basically gave away $70 worth of items for that 100 back, and gave $30 in change. 

Basically, you still lost $100 because the money was yours in the first place.