GMAT excercise 15
●Question 1. Sentence Correction
Direction: Correct the underlined part
Plants are more efficient at acquiring carbon than are fungi, in the form of carbon dioxide, and converting it to energy-rich sugars.
A. Plants are more efficient at acquiring carbon than are fungi
B. Plants are more efficient at acquiring carbon than fungi
C. Plants are more efficient than fungi at acquiring carbon
D. Plants, more efficient than fungi at acquiring carbon
E. Plants acquire carbon more efficiently than fungi
●Question 2. Critical Reasoning
The price the government pays for standard weapons purchased from military contractors is determined by a pricing method called “historical costing.” Historical costing allows contractors to protect their profits by adding a percentage increase, based on the current rate of inflation, to the previous year’s contractual price.
Which of the following statements, if true, is the best basis for a criticism of historical costing as an economically sound pricing method for military contracts?
A. The government might continue to pay for past inefficient use of funds.
B. The rate of inflation has varied considerably over the past twenty years.
C. The contractual price will be greatly affected by the cost of materials used for the products.
D. Many taxpayers question the amount of money the government spends on military contracts.
E. The pricing method based on historical costing might not encourage the development of innovative weapons.
●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.
(y+3)(y-1)-(y-2)(y-1)=r(y-1), what is the value of y ?
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
1<=n<=60 n integer. What is the probability that n(n+1)(n+2) is divisible by 6 ?
A. 1/2 B. 2/3 C. 3/4 D. 4/5 E. 1
●Answer to Q1: C
In A and B, ‘at acquiring carbon’ is misplaced because the expression should be placed behind the subordinate conjunction ‘than’ to be parallel with ‘converting it to energy-rich sugars’. And if the expression of D is put in the line, the whole expression becomes a fragment, not a complete sentence. In E, there is no expression that can be parallel with ‘converting it to energy-rich sugars’. So, the answer is C.
●Answer to Q2: A
The statement assumes that the government is now paying money for standard weapons reasonably. Otherwise, historical costing can’t be justified just because the contractors protect their profits by adding a percentage increase, based on the current rate of inflation, to the previous year’s contractual price. So, if an answer choice raises the possibility that the government may pay for standard weapons inappropriately, it is the best answer choice to criticize historical costing as an economically sound pricing method for military contracts. It is the answer choice of A.
●Answer to Q3: E
(y+3-y+2)(y-1)=r(y-1), 5(y-1)=r(y-1), (5-r)(y-1)=0, If 2) ==> 1) and 2) r=5, (5-5)(y-1)=0, 0(y-1)=0, y are all numbers, NOT sufficient, therefore the best answer is E.
●Answer to Q4: E
Because the product of 3 consecutive integers is a multiple of 6. the probability is 60/60=1, therefore the best answer is E.