False question as you assume the money you have deposited is put into a drawer called "freetx cash" and then lent out again as a lump sum with your name on it. But in real life, you know that's not how banks work. The $20 you take back for lunch is just cash from the pool of funds the bank works with. Its not part of the $100 cash you deposited.
I suggest you read "Modern Money Mechanics" published by no other than the Federal Reserve Bank of Chicago.
Pay attention to page 6:
"...Banks do not really pay out loans from the money they receive as deposits. If they did this, no additional money would be created. What they do when they make loans is to accept promissory notes in exchange for credits to the borrowers transaction accounts. Loans (assets) and deposits (liabilities) both rise [by the same amount].