There is a project that A alone takes 36 days to complete, B alone takes 30 days to complete, and C alone takes 48 days to complete. Now A, B, and C are working at the same time. During the working period, C has rested for a whole number of days, while A and B have been working until the completion of the project. It also took a whole number of days to complete the project. So, how many days did C rest?
有一项工程，甲单独做需36天完成，乙单独做需30天完成，丙单独做需48天完成．现在由甲、乙、丙三人同时做，在工作期间，丙休息了整数天，而甲和乙一直工作至完成，最后完成这项工程也用了整数天．那么，丙休息了多少天？
<result>11</result>