Is |x|/x equals to 1?

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Is |x|/x equals to 1?

by Max@Math Revolution » Fri Apr 29, 2016 7:18 pm
Is |x|/x equals to 1?

1) x>0
2) x<1


* A solution will be posted in two days.
Source: — Data Sufficiency |

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by Max@Math Revolution » Wed May 04, 2016 6:46 am
If we modify the original condition, we can write |x|/x=1? as |x|=x?. Hence, the question becomes x>0?. Thus, the correct answer is A.

- Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

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by 800_or_bust » Thu May 05, 2016 10:24 am
Max@Math Revolution wrote:Is |x|/x equals to 1?

1) x>0
2) x<1


* A solution will be posted in two days.
The correct answer is A.

Choice (1) is sufficient because the absolute value of any positive number x is equal to x. Therefore, the expression would simplify to x/x = 1.

Choice (2) is insufficient because x could be negative, in which case, the absolute value of x equals -x, and the expression would simplify to (-x)/x = -1. Or x could be zero, in which case the expression is undefined (due to division by zero).
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