If $x$ is a positive number, then which of the following fractions has the greatest value?
Aptitude
Simplification
Difficulty: Easy
Choose an option
-
Ax / x
-
Bx / (x + 1)
-
C(x + 1) / x
-
D(x + 2) / (x + 3)
Answer
Correct Answer: (x + 1) / x
Explanation
### Concept & Logic
This problem analyzes variables inside simple algebraic fractions. A fraction is maximized when its numerator is larger than its denominator (improper fraction value $> 1$).
### Step-by-Step Solution
* **Analyze Option (a):**
$\frac{x}{x} = 1$ (Always exactly equal to 1 for any positive number).
* **Analyze Option (b):**
$\frac{x}{x+1}$ (Since the numerator is smaller than the denominator, this value is always $< 1$).
* **Analyze Option (c):**
$\frac{x+1}{x} = 1 + \frac{1}{x}$ (Since the numerator is strictly greater than the denominator, this value is always $> 1$).
* **Analyze Option (d):**
$\frac{x+2}{x+3}$ (Since the numerator is smaller than the denominator, this value is always $< 1$).
* **Conclusion:**
Option (c) is the only fraction expression that produces a value strictly greater than 1, making it the greatest value among all choices.
### Exam Strategy & Shortcut
Plug in a basic integer value for $x$, such as $x = 1$:
Option (a): $\frac{1}{1} = 1$
Option (b): $\frac{1}{2} = 0.5$
Option (c): $\frac{2}{1} = 2$
Option (d): $\frac{3}{4} = 0.75$
Comparing the absolute values shows that 2 is unambiguously the greatest value.
### Common Pitfall
Overcomplicating the variable structure with derivative inequalities can lead to wasted time. Simple classification into proper ($<1$) and improper ($>1$) states resolves the expression relationship immediately.
### Final Answer
**Therefore, the correct answer is (x + 1) / x.**