If d denotes a decimal, is d ≥ 0.5?
(1) When d is rounded to the nearest tenth, the result is 0.5.
(2) When d is rounded to the nearest integer, the result is 1.
The OA is B.
I don't understand how can I show that the correct answer is B. Experts, may you help me here? Thanks in advanced.
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If d denotes a decimal, is d ≥ 0.5?
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Target question: Is d ≥ 0.5?VJesus12 wrote:If d denotes a decimal, is d ≥ 0.5?
(1) When d is rounded to the nearest tenth, the result is 0.5.
(2) When d is rounded to the nearest integer, the result is 1.
Statement 1: When d is rounded to the nearest tenth, the result is 0.5.
There are several values of d that satisfy statement 1. Here are two:
Case a: d = 0.51 (we get 0.5 when 0.51 is rounded to the nearest tenth). In this case, the answer to the target question is YES, it IS the case that d ≥ 0.5
Case b: d = 0.49 (we get 0.5 when 0.49 is rounded to the nearest tenth). In this case, the answer to the target question is NO, it is NOT the case that d ≥ 0.5
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: When d is rounded to the nearest integer, the result is 1
If we get 1 when d is rounded to the nearest integer, then we know that 0.5 ≤ d < 1.5[/color]
So, it MUST be the case that d ≥ 0.5
Since we can answer the target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
