18号以后数学几经对答案啦~~

烨子

141. on Jane's credit card account, the average daily balance for a 30-day billing cycle is the average(arithmetic mean)of the daily balances at the end of each of the 30 days.At the beginning of a certain 30-day billing cycle,Jane's credit card account had a balance of  $600.Jane made a payment of $300 on the account during the billing cycle.If no other amounts were added to or subtracted form the account during the billing cycle,what was the average daily balance on Jane's account for the billing cycle?

(1)Jane's payment was credited on the 21st day of the billing cycle

(2)The average dialy balance through the 25th day of the billing cycle was $540

答案C

这题我觉得答案不对啊

是不是两个单独都可以啊 D..

大家帮忙解答啊....

烨子

呵呵

[此贴子已经被作者于2007-10-23 18:53:08编辑过]

lzkisslife

以下是引用qianrene在2007-10-23 16:35:00的发言：

434一序列的数的range是24.7，每一项都加上6，新序列的range再除以10，求结果。

答案 2.47

435.DS: 一個數軸，上面有四個點 a, b, c, d ，四點之間等距，問點 a + c = ?
(1) a + b = -8
(2) a + d = 0

请问这题是哪天的JJ呢，好象没见过呀，是不是换题前的哦？

哦 当时没看清就做了 是17号的 呵呵

lzkisslife

以下是引用烨子在2007-10-23 16:42:00的发言：

141. on Jane's credit card account, the average daily balance for a 30-day billing cycle is the average(arithmetic mean)of the daily balances at the end of each of the 30 days.At the beginning of a certain 30-day billing cycle,Jane's credit card account had a balance of  $600.Jane made a payment of $300 on the account during the billing cycle.If no other amounts were added to or subtracted form the account during the billing cycle,what was the average daily balance on Jane's account for the billing cycle?

(1)Jane's payment was credited on the 21st day of the billing cycle

(2)The average dialy balance through the 25th day of the billing cycle was $540

答案C

这题我觉得答案不对啊

是不是两个单独都可以啊 D..

大家帮忙解答啊....

D啦D啦 我错啦~~

jq102854

这题我觉得答案不对啊

lzkisslife

黄色OG11上的 原题你去看下吧

peter_zbk

以下是引用lzkisslife在2007-10-23 16:29:00的发言：
我选的是E 不是B啊~~第二个不能单独得出结论

为什么不是C啊，前提是满足两个条件，所以无论abcd的顺序，c与a的距离都能求吧~

lzkisslife

17楼~可以求但不唯一