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If 1 < p < 2, is the tenths’ digit of the decimal representation of p equal to 9?
(1) p + 0.01 < 2
(2) p + 0.1 > 2
Target question: Is the tenths digit of p equal to 9? Given: 1 < p < 2 Statement 1: p + 0.01 < 2 Subtract 0.01 from both sides of the inequality to get: p < 1.99
We also know that
1 < p < 2So, we can now conclude that 1 < p < 1.99
There are several values of p that satisfy statement 1. Here are two:
Case a: p = 1.5, in which case, the answer to the target question is
the tenths digit is 5Case b: p = 1.4, in which case, the answer to the target question is
the tenths digit is 4Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: p + 0.1 > 2Subtract 0.01 from both sides of the inequality to get: p > 1.9
We also know that
1 < p < 2So, we can now conclude that 1.9 < p < 2
If p is greater than 1.9 and less than 2, then p = 1.9something
In other words, the answer to the target question is
the tenths digit is 9Since we can answer the
target question with certainty, statement 2 is SUFFICIENT
Answer: B
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