Re: P, Q, R, S, and T represent five distinct points on the circumference
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04 Aug 2020, 13:35
The explanation in the Princetown review:
This is a Yes/No Data Sufficiency question with unknown points in the question and in the statements, so Plug In values for P,Q,R,S, and T. The task of a Yes/No Data Sufficiency is to determine whether the information in the statements produces a consistent Yes or No response for any value that satisfies the statement(s). Evaluate the statements one at a time.
Evaluate Statement (1). Draw the three points Q, S, and T on the circle, and place T further from Q than S is from Q, which satisfies the statement. Since points P and R remain unknown, it is possible to draw these points on the circle in such a way that arc PQR is longer than arc RST, and the answer to the question is “Yes”. However, it is also possible to draw the points on the circle in such a way that arc PQR is shorter than arc RST, and the answer to the question is “No”. When two sets of values that satisfy the statement yield two different answers to the question, the statement is insufficient. So, write down BCE.
Now evaluate Statement (2). Draw the three points P, S, and T on the circle, and place S further from T than P is from T, which satisfies the statement. Since points Q and R remain unknown, it is possible to draw these points on the circle in such a way that arc PQR is longer than arc RST, and the answer to the question is “Yes”. However, it is also possible to draw the points on the circle in such a way that arc PQR is shorter than arc RST, and the answer to the question is “No”. When two sets of value that satisfy the statement yield two different answers to the question, the statement is insufficient. Eliminate choice B.
Now evaluate both statements together. While the two statements together place restrictions on the distances between the points, the location of R is unknown. Draw the circle such that chords PQ and ST are of approximately equal length. R may now be placed in positions that provide an answer of both “Yes” and “No”. When two sets of values that satisfy the statements yield two different answers to the question, the statements are insufficient. Eliminate choice C.