回复：生活中的数学 2　

来源: 于 2010-07-04 19:33:10 [旧帖] [给我悄悄话] 本文已被阅读：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