2. 外语
  3. If x + y+z>0, is z> 1 ? (1) z>x + y+1 (2) x+y+1

If x + y+z>0, is z> 1 ? (1) z>x + y+1 (2) x+y+1

admin2022-10-18  25
问题 If x + y+z>0, is z> 1 ?
(1) z>x + y+1
(2) x+y+1<0
选项 A、Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B、Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C、BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D、EACH statement ALONE is sufficient.
E、Statements (1) and (2) TOGETHER are NOT sufficient.
答案B
解析 Determine if z > 1 is true.
(1)     Given that z > x + y + 1, by adding z to both sides, it follows that 2z>x+y + z + 1. Also, x+y + z+1 > 1 because x + y + z > 0.Thus, 2z > 1 and z >1/2.  It is possible that z > 1 is true and it is possible that z > 1 is not true. For example, if z = 1.1 and x = y = 0, then x + y + z > 0 and z > x + y + 1 are both true, and z > 1 is true. However, if z = 1, x = -0.5 and y = -0.25,x+y+ z > 0 and z > x+ y+ 1 are both true, and z > 1 is not true; NOT sufficient.
(2)     Given that x + y + 1 < 0, it follows that 1 < -x - y. It is also given that x + y + z > 0, so z > -x -y or -x-y < z. Combining 1 < -x - y and -x - y < z gives 1 < z or z > 1; SUFFICIENT.
The correct answer is B;
statement 2 alone is sufficient.
转载请注明原文地址:https://kaotiyun.com/show/MttO777K
本试题收录于： GMAT QUANTITATIVE题库GMAT分类
0

GMAT QUANTITATIVE

GMAT

相关试题推荐
随机试题
最新回复(0)