【数学讨论稿】十月溯雪讨论稿301-400 (Nov17更新至400)

postgraduate201

hello
"M被n除之后呢余数为5，然后问n是多少？（应该是这样）
A． m被8除后余1
B． n小于7

let say M=ny+5
ny must > 5
Since we dont know y
Option B is not sufficient?

VG.BurNing

postgraduate201 发表于 2015-11-12 22:02
hello
"M被n除之后呢余数为5，然后问n是多少？（应该是这样）
A． m被8除后余1

The remainder would have to be less than the divisor, or the quotient would be greater since the remainder could be reformed as "n*divisor"+"real remainder".
So B is sufficient due to n, which is the divisor, would have to be greater than 5, which is the remainder.
5<n<7 can conspicuously lead to the only valid value of the integer n, 6.

小肉猫不爬树

VG.BurNing 发表于 2015-11-12 16:59
并没有理解

感觉意思是 t等于比r多s这么多的一个数   然后问题是下面哪一个是比t少r这么多的值？
不知说清楚了么、、、、

kayxiaomi

VG.BurNing 发表于 2015-11-12 23:03
The remainder would have to be less than the divisor, or the quotient would be greater since the r ...

如果n不为整数呢？

qyhz0222

请问数学君340题是少了条件么？
感觉没看懂呢。。。

147852gmat

kayxiaomi 发表于 2015-11-13 04:06
如果n不为整数呢？

In mathematics, the remainder is the amount "left over" after performing some computation. In arithmetic, the remainder is the integer "left over" after dividing one integer by another to produce an integer quotient (integer division) ----from wiki

n只能是整数

147852gmat

VG.BurNing 发表于 2015-11-12 16:59
并没有理解

T is S more than R, which of the following is R less than T?

T= S+R
T-R=S

147852gmat

qyhz0222 发表于 2015-11-13 06:25
请问数学君340题是少了条件么？
感觉没看懂呢。。。

没少条件， 题目是少细胞分裂，每半小时，分裂出来的数量就是之前的三倍。 问分裂四小时后的数量 和 分裂两小时的ratio

4小时分裂了8次。。两小时分裂了4次
也就是 3^(8)/3^(4) = 81/1

147852gmat

数学君，356题你好像理解错题了，可以再看一下么

4^(-4)/[1/16^(-3)]=?

4^(-4) is 1/4^(4)
16^(-3) is 1/16^(3), then 1/1/16^(3)=16^(3)

[1/4^(4)]/16^(3) = 1/4^(10)=4^(-10)

vivi00

lz你好，请问下360题，

求 G∪P 是否为空集？

（1) (G∪P)∩G=G

如果(G∪P)是空集，那(G∪P)∩G应该是等于空集，所以根据条件1应该就可以判断出来了