At her favorite restaurant, sami orders and enjoys the lobster special, which was listed at $30 on the menu. when the bill arrives, sami tries to execute a clever ploy she learned about in her business law class: she writes a check to the restaurant for $20 and writes "full settlement" across the top. the waiter accepts the check without looking at it, and the restaurant manager later deposits it in the restaurant's bank account. is this a liquidated or an unliquidated debt? is sami off the hook for the last $10?