GMAT Exercise - 8
●Question 1. Sentence Correction
Direction: Correct the underlined part
Construction of the Roman Colosseum, which was officially known as the Flavian Amphitheater, began in A.D. 69, during the reign of Vespasian, was completed a decade later, during the reign of Titus, who opened the Colosseum with a one-hundred-day cycle of religious pageants, gladiatorial games, and spectacles.
A. which was officially known as the Flavian Amphitheater, began in A.D. 69, during the reign of Vespasian,
B. officially known as the Flavian Amphitheater, begun in A.D. 69, during the reign of Vespasian, and
C. which was officially known as the Flavian Amphitheater, began in A.D. 69, during the reign of Vespasian, and
D. officially known as the Flavian Amphitheater and begun in A.D. 69, during the reign of Vespasian it
E. officially known as the Flavian Amphitheater, which was begun in A.D. 69, during the reign of Vespasian, and
●Question 2. Critical Reasoning
A company plans to develop a prototype weeding machine that uses cutting blades with optical sensors and microprocessors that distinguish weeds from crop plants by differences in shade of color. The inventor of the machine claims that it will reduce labor costs by virtually eliminating the need for manual weeding.
Which of the following is a consideration in favor of the company’s implementing its plan to develop the prototype?
A. There is a considerable degree of variation in shade of color between weeds of different species.
B. The shade of color of some plants tends to change appreciably over the course of their growing season.
C. When crops are weeded manually, overall size and leaf shape are taken into account in distinguishing crop plants from weeds.
D. Selection and genetic manipulation allow plants of virtually any species to be economically bred to have a distinctive shade of color without altering their other characteristics.
E. Farm laborers who are responsible for the manual weeding of crops carry out other agricultural duties at times in the growing season when extensive weeding is not necessary.
●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.
Is |a^2 -b^2|<6?
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
●Answer to Q1: C
Since the verb ‘began’ in the underline should be linked with the verbal phrase ‘was completed’, which is located out of the underline, the answer choice A needs a conjunction such as ‘and’ at the end of the expression. Also, the answer choice B is wrong because it is connecting the participle ‘begun’ with the verbal phrase ‘was completed’ through ‘and’. In D, the pronoun ‘it’ is needless repeated expression. In other words, the subject of the whole sentence ‘construction of the Roman Colosseum’ should be connected directly with the verbal phrase ‘was completed’. And, if the answer choice E is put into the underline, the whole expression including the expression out of the underline is not a complete sentence but a sentence fragment. So, the answer is C.
●Answer to Q2: D
Explanation: The question is asking for an answer choice that supports the conclusion that new weeding machine will eliminate the need for manual weeding. Choice (A) and (B) actually weakens the conclusion because if there is a large variation in shade of color between weeds, the effectiveness of the machine will deteriorate. Choice (C) emphasizes effectiveness of manual weeding. Choice (D) is the right answer that plants can be bred to have different shade of colors which will make the machine’s usage more effective. Choice (E) is in favor of manual weeding because laborers actually do more than just weeding.
●Answer to Q3: C
Because the number of the variables is 2, it is possible to the answer be C, 1) & 2) together, since the question is “Is |a-b||a+b|<6?”, therefore the best answer is C.