Difficulty: Medium
Correct Answer: 2
Explanation:
Introduction / Context:
This question involves solving two linear inequalities in a single variable and then finding the values of x that satisfy both conditions simultaneously. Such problems appear frequently in aptitude tests to check understanding of algebraic manipulation and the concept of solution sets for inequalities.
Given Data / Assumptions:
Concept / Approach:
We will simplify each inequality step by step and express its solution as an interval. After that, we find the intersection of these intervals, since both inequalities must hold at the same time. Finally, we check which option lies inside the common interval. Linear inequalities are solved using the same algebraic steps as equations, but we pay attention to the direction of the inequality symbol especially when multiplying or dividing by negative numbers.
Step-by-Step Solution:
First inequality: 2x + 3(5 - 2x) > 2 - 3x. Expand the bracket: 2x + 15 - 6x > 2 - 3x.Combine like terms: (2x - 6x) + 15 > 2 - 3x gives -4x + 15 > 2 - 3x.Add 4x to both sides: 15 > 2 + x which simplifies to x < 13.Second inequality: 2 - 3x < 2x - x/3. Combine terms on the right: 2x - x/3 = (6x - x)/3 = 5x/3.So we have 2 - 3x < 5x/3. Add 3x to both sides: 2 < 5x/3 + 3x = 5x/3 + 9x/3 = 14x/3.Multiply both sides by 3: 6 < 14x, so x > 6/14 = 3/7.Thus, the combined solution is 3/7 < x < 13.Among the options, only x = 2 lies in this open interval, so 2 is the correct choice.
Verification / Alternative check:
We can substitute x = 2 directly into both inequalities. For the first: 2x + 3(5 - 2x) = 4 + 3(1) = 7, and 2 - 3x = 2 - 6 = -4. Since 7 > -4, the first inequality holds. For the second: 2 - 3x = 2 - 6 = -4 and 2x - x/3 = 4 - 2/3 = 10/3 which is about 3.33. Since -4 < 10/3, the second inequality holds as well. This confirms that x = 2 satisfies both.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
2
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