GMAT exercise 21
●Question 1. Sentence Correction
Direction: Correct the underlined part
Neither First Lady Eleanor Roosevelt nor Secretary of Labor Frances Perkins sought recognition by the press, and both cautiously allowed others of the Roosevelt brain to take credit for the genesis of historic programs in public employment, relief, and social security that were in large measure what they had been responsible for.
A. to take credit for the genesis of historic programs in public employment, relief, and social security that were in large measure what they had been responsible for
B. to take credit for the genesis of historic programs in public employment, relief, and social security for which the two women were in large measure responsible
C. taking credit for the genesis of historic programs in public employment, relief, and social security for which the two women were in large measure responsible
D. taking credit for the genesis of historic programs in public employment, relief, and social security that were in large measure what they were responsible for
E. taking credit for the genesis of historic programs in public employment, relief, and social security which were largely their responsibility
●Question 2. Critical Reasoning
Sunflowers growing in pots were placed, with their roots submerged, in the pond contaminated with radioactive elements. The sunflowers kept growing; in the process, they absorbed radioactive elements. Within twelve days, 85 percent of the radioactive elements were removed from the water, which is no less than can be accomplished with the much more expensive conventional filtration techniques. Scientists therefore propose using sunflowers for decontamination wherever there are radioactively contaminated ponds.
Which of the following, if true, points to a limitation on the applicability of the proposed method of decontamination?
A. Some plants other than sunflowers can also remove radioactive elements from water.
B. The water in many ponds contaminated with radioactive elements is so cold that it would kill sunflowers whose roots were submerged in it.
C. Sunflowers that grow with their roots submerged in water grow less well than sunflowers growing under optimal conditions on dry land.
D. Only species of sunflowers with large leaves can have their roots submerged in water and still keep growing.
E. In ponds in which the circulation of the water is artificially increased, sunflowers absorb radioactive elements far faster than they do in other ponds.
●Question 3. Data Sufficiency
Directions: In this problem, a question is followed by two statements containing certain data. You are to determine whether the data provided by the statements are sufficient to answer the question. Choose the correct answer based upon the statement’s data and your knowledge of mathematics.
The lifetimes of all the batteries produced by a certain company in a year have a distribution that is symmetric about the mean m. If the distribution has a standard deviation of d, what percent of the distribution is greater than m+d?
1) 68 percent of the distribution lies in the interval from m-d to m+d, inclusive.
2) 16 percent of the distribution is less than m-d.
A. statement 1 alone is sufficient, but statement 2 alone is not sufficient to answer the question
B. statement 2 alone is sufficient, but statement 1 alone is not sufficient to answer the question
C. both statements taken together are sufficient to answer the question, but neither statement alone is sufficient
D. each statement alone is sufficient
E. statements 1 and 2 together are not sufficient, and additional data is needed to answer the question
●Question 4. Problem Solving
If x, y are positive numbers and x+y=1, which of the following can be the value of 100x+200y?
I. 80 II. 140 III. 199
A. I only B. Ⅱonly C. Ⅰ,Ⅱ only D. Ⅱ,Ⅲ only E. Ⅰ,Ⅱ and Ⅲ
●Answer to Q1: B
In terms of the idiom of the verb ‘allow’, which is out of the line, each answer choice should begin with ‘to take’. But in A, the pronoun ‘they’ can be misunderstood as ‘others of the Roosevelt brain trust’. In addition, the answer choice of A, compared with B, is somewhat wordy because it used needlessly the relative clause. So, the answer is B.
●Answer to Q2: B
The question needs the answer choice that can weaken the conclusion that using sunflowers for decontamination is an effective way of removing the radioactive elements in contaminated ponds. Therefore, any answer choice that can point to the circumstance in which sunflowers can’t play the role of removing the radioactive elements can achieve the weakening of the conclusion. In terms of this logical relation, all the answer choices except for B are irrelevant or strength the conclusion adversely. So, the answer is B.
●Answer to Q3: D
Because condition 1)= condition 2), and the percent of the distribution greater than m+d is 16%, the best answer is D
●Answer to Q4: C
100x+200(1-x)=200-100x<200, and 100(1-y)+200y=100+100y>100, therefore the best answer is C.