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13 Mar 2020, 05:19
Kudos
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A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
15%
(low)
Question Stats:
79% (01:15) correct
21%
(01:42)
wrong
based on 158
sessions
History
Date
Time
Result
Not Attempted Yet
If c and d are integers, is c − 3d even?
(1) c and d are odd.
(2) c − 2d is odd.
(1) c and d are odd.
(2) c − 2d is odd.
13 Mar 2020, 06:09
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Bunuel
Step 1: Analyze Question Stem
- • c and d are integers.
• We need to find if c – 3d = even or not.
• For c - 3d to be even, there can be two possibilities:
- o Case 1: Both c and d are even.
- c – 3d = Even – Odd * Even = Even
- c – 3d = Odd – Odd * Odd = Even
Thus, only when both c and d are even or both are odd, then c – 3d is even. Keeping this in mind, let’s analyze the statements.
Step 2: Analyze individual statements
Statement 1: c and d are odd.
- • We know that if both c and d are odd, then c – 3d is even.
Statement 2: c − 2d is odd.
- • c – even * d = odd
• c – even = odd
• c = odd + even = odd
Hence, statement 2 is not sufficient and the correct answer is Option A.
17 May 2020, 13:29
Kudos
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Hello Bunuel ,
Can we definitively say that A is the correct answer?
What if C=9 and D=3, then c-3d is 9-3(3) = Zero, thus not even nor odd.
Would E be the true correct answer for this problem?
Can we definitively say that A is the correct answer?
What if C=9 and D=3, then c-3d is 9-3(3) = Zero, thus not even nor odd.
Would E be the true correct answer for this problem?
