ROckHIsT wrote:
The symbol Ω represents one of the following operations: addition, subtraction, multiplication or division. What is the value of 1 Ω 1?
(1) 2 Ω 2 = 4
(2) 0 Ω 1 = 0
Target question: What is the value of 1 Ω 1? Given: Ω represents one of the following operations: addition, subtraction, multiplication or division. Statement 1: 2 Ω 2 = 4 2 - 2 = 0, so Ω CANNOT represent subtraction.
2 ÷ 2 = 1, so Ω CANNOT represent division.
2 + 2 = 4, so Ω COULD represent addition. In this case, the answer to the target question is
1 Ω 1 = 1 + 1 = 22 x 2 = 4, so Ω COULD represent multiplication. In this case, the answer to the target question is
1 Ω 1 = 1 x 1 = 1Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: 0 Ω 1 = 0 0 - 1 = -1, so Ω CANNOT represent subtraction.
0 ÷ 1 = 0, so Ω COULD represent division. In this case, the answer to the target question is
1 Ω 1 = 1 ÷ 1 = 10 + 1 = 1, so Ω CANNOT represent addition.
0 x 1 = 0, so Ω COULD represent multiplication. In this case, the answer to the target question is
1 Ω 1 = 1 x 1 = 1IMPORTANT: from statement 2, we can conclude that Ω represents EITHER division OR multiplication. Because Ω could represent two different operations, some students will incorrectly conclude that statement 2 is not sufficient.
However, the target question is NOT asking "What operation does Ω represent?" The target question is asking
What is the value of 1 Ω 1?In BOTH of the above cases (for statement 2),
1 Ω 1 = 1.
Since we get only one answer to the
target question, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent