Assets are items or properties that you own, and that are valuable to you. Liabilities are things that you have to pay for as a result of you using something. So, having that in mind, Quincy's liabilities are rent, student loan, and utilities, whereas his assets are cash, stocks, and jewelry.
He gets cash when he finishes his work, he gets money from stocks, and he has his jewelry that he either bought or got as a gift that he can sell for money.
