回複：生活中的數學 2　

來源: 於 2010-07-04 19:33:10 [舊帖] [給我悄悄話] 本文已被閱讀：次

You should re-charge 14 mins.
14 +3 -15=2 mins, that is your missed 2 mins.
You can watch the remained 43 mins.
14x2+15=43 mins=45+15-14-3mins