本题已出现6次
疑似208. DS:1.003X是整数?A.X/1000是整数。B. X/18000是整数 答案:D
319. XY>x/y?
(a), xy>0 ; (b), y<o ; 我选的E
类比于169. is XY > x/Y?
1) X<0 ; 2) XY>0 ;Ans: E
同236。
可以直接从整除的角度了思考 N+X需要同时能被5和7整除,
∵X被5除余1 ,∴X加上4后就可以被5整除,
∵X被7除余3,∴X加上4后就可以被7整除, N=4
另,ESeraph的解释:
X=5a+1=7b+3. so 5a=7b+2. 5a的结果只能是5,10,15,20...
so 7b的个位数必然是3 or 8. 而7的倍数各位是3 or 8的只有4,14,24.. / 9,19,29...
so we can find the minimun X= 5*6+1 = 7*4+3 where a=6 and b=4
so X=31. N=4.
321. 一个长方形的短边接了一个半圆,问整个图形的面积能否求出?
a.长方形的面积是24 ; b.长方形的宽是3,长是8, 选B
同237. 给出一个半圆柱槽(trough)的图形(圆柱沿直径竖着切一半),告诉直径是2,半圆柱的容积是32,求长度。答案:64/Pi
一个圆形周长18派,未指明是大圆还是小圆。
出自GWD:
Of the families in City X in 1994, 40 percent owned a personal computer. The number of families in City X owning a computer in 1998 was 30 percent greater than it was in 1994, and the total number of families in City X was 4 percent greater in 1998 than it was in 1994. What percent of the families in City X owned a personal computer in 1998?
A. 50%
B. 52%
C. 56%
D. 70%
E. 74%
解: 设1994年有 100人, 有电脑的有 40人
则1998年有 104人, 有电脑的有 40×1.3=52人
52/104=50%
