GMAT数学易错考点—余数问题+例题!(下)
余数问题是GMAT数学常见题目,
差不多就是余数余数场场见,
所以你一定要好好掌握这类问题!
上次我们了解了:
GMAT数学易错考点—余数问题+例题!(上)
错过的GMATer们可以直接戳链接回顾☝
今天我们一起康康下半部分内容吧~
剩余定理(求被除数)
例6、When n is divided by 3, the remainder is 2; and when n is divided by 4, the remainder is 1.What is the remainder when the positive integer n is divided by 12?
A、1 B、2 C、3 D、5 E、6
解析:D
剩余定理:n=12x+5
特殊余数问题口诀
和同加和
余同加余
差同减差
注:最小公倍数作为周期
例7、When n is divided by 6, the remainder is 2; and when n is divided by 8, the remainder is 4.What is the remainder when the positive integer n is divided by 24?
A、2 B、4 C、10 D、15 E、20
解析:E
剩余定理:n=24x-4
例8、
(机经)小于500的正整数中,被7除余1,且被3除余2的数有多少?
解析:24
X=21n+8(公倍数作为周期)
21n+8<500:n=0时X=8;n=23时X=491
n∈[0,23]
一共就是24个
例9、When positive integer x is divided by 5, the remainder is 3; and when x is divided by 7, the remainder is 4. When positive integer y is divided by 5, the remainder is 3; and when y is divided by 7, the remainder is 4. If x > y, which of the following must be a factor of x - y?
A.12 B.15 C.20 D.28 E.35
解析:E
x÷5=a....3, y÷5=b....3,x-y与3-3关于5同余,余数是0,所以x-y是5的倍数。
x÷7=c....4, y÷7=d....4,x-y与4-4关于7同余,余数是0,所以x-y是7的倍数。
所以x-y的值应该既然是5的倍数,也是7的倍数。
例10、What is the remainder when prime number x is divided by 8?
(1)When x is divided by 2, the remainder is 1.
(2)When x is divided by 3, the remainder is 2.
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
解析:
条件1:X是奇数且是质数,除以8的余数不确定,如3,5,7除以8的余数分别为3,5,7。
条件2:X=3a+2(a=0或者a是奇数),除以8的余数不确定,如2,5除以8的余数分别为2,5。
条件1+条件2:X=6a-1(a是正整数),
,不充分。(剩余定理)
好啦~
以上就是成都申友GMAT给大家带来的
GMAT数学易错考点—余数问题+例题!(下)。
GMAT数学满分不容易,
搞定GMAT数学易错考点,
逐个击破Remainder重难考点非常有必要!
欢迎大家持续关注我们后面更新的内容。
为了帮助大家迅速提升GMAT实力,成都申友GMAT七月经典全程突破班来啦!
戳下方二维码添加洒托小学姐微信
领取GMAT备考资料 | 问题解答 | 加入备考群

参与讨论

香港中文大学商学院硕士请要点都在这,25年3月31日截止申请!

速看!25fall英国硕士申请截止日期!热门专业“抢位赛”已开启!

新加坡国立大学(NUS)商学院已经开放申请!你准备好了吗?

GMAT封闭班!抓住寒假,出分、Offer都拿下!!!

GMAT备考攻略!GMAT小白应该如何备考?(附免费资料哦~)

GMAT总是在650分上下徘徊,700分真有这么遥不可及吗?

纯干货 | 备考GMAT前,这5件事你必须知道!

GMAT封闭班!抓住寒假,出分、Offer都拿下!!!

GMAT备考 | 零基础如何备考GMAT,早日出分?

重磅消息!GMAT官宣取消一生考8次的限制,10月31日实施!