Critical Reasoning Question 22: Manufacturing

Smith Products fabricates machine tools that are essentially identical to those produced by Jackson Manufacturing.  For both companies, raw materials represent about two-thirds of the cost of manufacturing the machine tools.  To gain an edge over Jackson Manufacturing, Smith Products should purchase its raw materials from a new supplier advertising much lower prices.

Which of the following, if true, would most weaken the argument above?

A.      Smith Products spends more on employees’ wages than Jackson Manufacturing does.

B.      Smith’s current supplier provides raw materials of exceeding high quality.

C.      The market for machine tools has been declining for several years.

D.      The new supplier’s materials are of low quality and would reduce the lifespan of Smith machine tools by half, causing sales to decline.

E.       The plant manager for Smith Products is planning to increase the plant’s efficiency.

Think you know the answer?

The correct answer is D.

The conclusion that Smith Products could gain an advantage by purchasing lower-cost raw materials is based on the evidence that raw materials represent the largest proportion of costs for both Smith and Jackson.  For the conclusion to hold, Smith must assume the new raw materials will not have any other negative effects on its business.  So, to weaken the argument, look for a choice that casts doubt on this assumption.  (D) does so by stating that the low quality of the new materials will cause a drop in sales.  If that occurs, using the new supplier will not create an advantage for Smith Products, and so (D) is the answer.  (A) and (E) indicate other ways that Smith might gain an advantage, but they don’t have any bearing on whether changing suppliers would create an advantage.  (B) is similarly irrelevant; even if true, it doesn’t provide any reason Smith should not use the new supplier.  (C) is out of the scope of the argument.