I need typed answer with explanation. Don't use AI BOT otherwise I will report to your answer. Give me a proper explanation I will thumb up.

Barbara has two business assets that were either wholly or partially destroyed during a tornado. One was a truck with a basis of $34,000 and a market value of $30,000 before the tornado and a value of $20,000 after. The other was storage and utility building with a basis of $40,000, a market value of $30,000 before the tornado, and no value after due to total destruction. She received $40,000 of insurance proceeds for these two damaged assets. (CH6)

What is the amount of her deductible business casualty loss