以下是引用vivian128在2009/8/22 18:02:00的发言：Beginning in January of last year,Carl made deposits of $120 into his account on the 15th of each month for several consecutive months and then made withdrawals of $50 from the account on the 15th of each of the remaining months of last year. There were no other transactions in the account last year. If the closing balance of Carl's account for May of last year was $2600, what was the range of the monthly closing balances of Carl'saccount last year? (1) Last year the closing balance of Carl's account for April was less than $2625. (2) Last year the closing balance of Carl's account for June was less than $2675 选 C
不知道你读懂提没~ 意思是说 前几个月连续存120 之后剩下的几个月 每月连续取50 根据5月份的余额是2600 可以得出 4月份的余额应该是2480或者2650 7月份的余额应该是2720或者2550 根据1条件 4月份余额小于2625 得出4月份余额是2480 说明前五个月是连续存钱的 根据条件二 得出 7月份的月儿是2550 说明后几个月是连续取钱的 最后问range ~ 很容易解题了吧 | 
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发表于 2009-8-22 19:39:00
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