请教几道DATA SUFFICIENCY

xuyingkitty

都是新东方蓝皮书上的DATA SUFFICIENCY


10. Is triangle MNP isosceles?
(1) Exactly two of the angles, 角M and 角N, have the same measure
(2) 角N and 角P do not have the same measure.
答案是A,我选C.难道等边三角形也算在等腰里的？我记得有一题类似的，正方形就不属于长方形的。


22. A jewelry dealer initially offered a bracelet for sale at an asking price that would give a profit to the dealer of 40 percent of the original cost. What was the original cost of the bracelet?
(1) After reducing this asking price by 10 percent, the jewelry dealer sold the racelet at a profit of $403.
(2) The jewelry dealer sold the bracelet for $1,953.
答案是A， 我选D. 售价和报价一定不一样吗？


33. If l1, l2 and l3 are lines in a plane, is l1 perpendicular to l3?
(1) l1 is perpendicular to l2
(2) l2 is perpendicular to l3
答案是C, 我选E. 两个条件加起来能得出的不是平行么。。。


34. In a certain packinghouse, grapefruit are packed in bags and the bags are packed in cases. How many grapefruit are in each case that is packed?
(1) The grapefruit are always packed 5 to a bag and the bags are always packed 8 to a case.
(2) Each case is always 80 percent full.
答案是A, 我选C. 如果是A的话，没说一个case一定装满啊。


46. What fractional part of the total surface area of cube C is red?
(1) Each of 3 faces of C is exactly 1/2 red.
(2) Each of 3 faces of C is entirely white.


55. If x and y are consecutive odd integers, what is the sum of x and y?
(1) The product of x and y is negative.
(2) One of the integers is equal to -1.
答案是A,强烈怀疑答案错。


90. One kilogram of a certain coffee blend consists of x kilogram of type I coffee and y kilogram of type II coffee. The cost of the blend is C dollars per kilogram, where C = 6.5x + 8.5y. Is x<0.8?
(1) y>0.15
(2) C>= 7.30
答案是B，我选E


先谢过各位高人！

tkrayla

10
我觉得exactly是只确切的两个角相等 之前见过一道题 问两直线是否垂直 一个条件就是 一个角exactly等于其余三个角之一 而答案上那个条件推不出结论的
22
售价和报价不一定一样
33
因为平行 所以就不垂直啊 还是回答了问题
34
我觉得有always 就应该按常规来想。。。
46
没怎么看懂
55
答案没错 如果乘积是负数 又是连续奇数 x和y只可能是1和-1
和就是0
如果其中一个是-1
另一个可能是1或者-3 没有唯一答案
所以选A
90
它有个隐含条件 就是x+y=1
所以(1)一定不对
c=6.5x+8.5y=6.5x+8.5(1-x)>=7.3
得到 x<=0.6
所以选b
ps 这个看起来有点像XDF的题啊。。。。

zy02550

46是C吗？(1),(2) 联立得出1/4 surface is of cube C is red

xuyingkitty

谢谢ls啦!

46题继续等待高人解答

zhenzhu

46题是A么？

xuyingkitty

答案是C,我选A的。。。我觉得B是废话啊，A的意思不就是除了这三面每面有一半是红的，其余地方都不是红的么，管它是不是白的，不都能求出来么。。。谢谢楼上的几位了！
并继续等待高人解答46

fullmoon558

46题我记得之前有筒子发帖子问过，翻译应该是立方体C中红色占总面积的百分之几，条件一：有三个面每一面上都有1/2红色面积 条件二：有三个面每一面上全都是白色。 条件一，二加起来可以算出比例：（3*1/2+0）/6=1/4