The offer was accepted, and the contract was formed in June. Later that summer, Stanley and Hem informed Jones that they were having trouble erecting the structural steel because they were short on employees. As a result of delays caused by the problem, Stanley and Hem asked Jones for another $20,510 to cover their increased labor expenses, raising the total project cost to more than $66,000. Jones agreed to pay the additional amount. Would Jones have to pay the additional $20,510