If n and p are integers, is p > 0 ?
(1) n + 1 > 0
(2) np > 0
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.
N P是整数,P>0么?即问P是正整数么?
(1)n+1>0 n>-1 只有n没有跟P相关的;不充分。
(2)Np>0 只能说明np同号,有可能都为负整数;不充分。
联立:n>-1 n=0 n=1
NP>0 n又必须满足大于-1的正整数,所以n最小值也就是1,p>0
充分
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