扫描二维码，直接登录
题库 / Prep2007E2-DS-61
When the positive integer n is divided by 25, the remainder is 13. What is the value of n ?
(1) n < 100
(2) When n is divided by 20, the remainder is 3.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
还没有题目讲解（毕出老师会陆续发布对官方考题的解读，请保持关注）。
25k + 13 = 20m +3
25k + 10 = 20m
5k + 2 = 4m
m=(5k+2)/4 - m has to be integer.
k has to be even and not divisible by 4
(2) n=25m+13,m=(0,1,2,3……）; n=20k+3,k=(0,1,2,3……）
25m+13=20k+3-->25m+10=20k-->1.25m+0.5=k, 因为k,m各自是整数，所以m*0.25=0.5，m,k=(2,3),(6,8)……，往后无限延伸。