单项选择(2023年管理综合

一个分数的分子与分母之和为 38,其分子和分母都减去15,约分后得到1/3,则这个分数的分母与分子之差为【 】

A、1

B、2

C、3

D、4

E、5

答案解析

D

讨论

Fix integers a and b greater than 1. For any positive integer n, let rn be the (non-negative) remainder that bn leaves upon division by an. Assume there exists a positive integer N such that rn<2n/n for all integers n≥N.Prove that a divides b.给定大于1的整数a和b.对任意的正整数n,记rn为bn除以an的非负余数.若存在正整数N,使得对任意的n≥N,都有rn<2n/n.证明:a整除b.

已知a,b为正整数,a<b,且a,b互质.若关于x,y的不等式ax+by≤ab有且仅有2023组正整数解,则(a,b)=____________________(求出满足题意的所有可能数组).

设有理数r=p/q∈(0,1),其中p,q为互素的正整数,且pq整除3600.这样的有理数r的个数为________.

给定正整数k(k≥2)与k个非零实数a1,a2,⋯,ak.证明:至多有有限个k元整数组(n1,n2,⋯,nk),满足n1,n2,⋯,nk互不相同,且a1∙n1 !+a2∙n2 !+⋯+ak∙nk !=0.

设整数n≥4.证明:若n整除2n-2,则(2n-2)/n是合数.

Let m<n be positive integers. Start with n piles, each of m objects. Repeatedly carry out the following operation: choose two piles and remove n objects in total from the two piles. For which (m ,n) is it possible to empty all the piles?【译】设正整数m<n.起初一共有n 堆石子,每堆有 m块石子. 重复执行以下操作: 选择两堆石子,从这两堆中移除共n 块石子.问:对于怎样的 (m , n),可以移除所有石子?

Determine all composite integers n>1 that satisfy the following property:if d1,d2,⋯,dk are all the positive divisors of n with 1=d1<d2<⋯<dk=n, then di divides di+1+di+2 for every 1≤i≤k-2.译文:设1=d1<d2<⋯<dk=n是合数n的全部正因数,若对任意1≤i≤k-2,有di |di+1+di+2,求n.

使得n²+2023n为平方数的正整数n的最小值是__________.

求所有不超过100的正整数k,使得存在整数n,满足:k|(3n6+26n4+33n2+1)

In the sequence 7,76,769,7692,76923,769230,… ,the nth term is given by the first n digits after the decimal point in the expansion of 10/13=0.7692307692⋯.Prove that of the first 60 terms of the sequence, at least 49 have three or more prime factors (repeated prime factors are allowed; for example, 76=2×2×19 has three prime factors).【译】在10/13=0.7692307692⋯的十进制表示中,由小数点后的前n位数构成数列:7,76,769,7692,76923,769230,… ,求证:在该数列的前60项中,至少有49项有三个或以上的素因子(包含重复的素因子,例如76=2×2×19有三个素因子).