作者OdysseyGRE (Odyssey)
看板GRE_Verbal
標題[數學]請教!!
時間Wed Aug 1 20:46:39 2007
1. The "reflection" of a postive integer is obtained by
reversing its digits. For example, 321 is the
reflection of 123. The difference between a five-digit
integer and its reflection must be divisible by which
of the following?
Ans: 9
2. If 55 percent of a group of people have brown hair and
80 percent of the same group do NOT have red hair, what
fraction of those who do NOT have brown hair and red hair?
Ans: 4/9
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※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 61.216.100.252
1F：推 Pluronics:(10000a+1000b+100c+10d+e) 61.216.100.161 08/01 21:07
2F：→ Pluronics:-(10000e+1000d+100c+10b+a) 61.216.100.161 08/01 21:07
3F：→ Pluronics:=9999a+990b-990d-9999e 61.216.100.161 08/01 21:07