Six times the complement of an angle is 12° less than twice its supplement. Find the measure of the angle.
Aptitude
Plane Geometry
Difficulty: Medium
Choose an option
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A48°
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B96°
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C24°
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D58°
Answer
Correct Answer: 48°
Explanation
Introduction / Context:Complementary angles sum to 90°, and supplementary angles sum to 180°. The statement links linear expressions of the same unknown through these definitions.
Given Data / Assumptions:
- Angle = x°.
- Complement = 90 − x; supplement = 180 − x.
- Condition: 6(90 − x) = 2(180 − x) − 12.
Concept / Approach:Translate to an equation in x and solve. Keep complements and supplements distinct.
Step-by-Step Solution:
6(90 − x) = 2(180 − x) − 12540 − 6x = 360 − 2x − 12540 − 6x = 348 − 2x540 − 348 = 6x − 2x192 = 4x ⇒ x = 48°Verification / Alternative check:Complement = 42°, supplement = 132°. LHS = 6*42 = 252; RHS = 2*132 − 12 = 264 − 12 = 252 ✓.
Why Other Options Are Wrong:They fail the given linear relation when checked.
Common Pitfalls:Mixing up 90 − x and 180 − x; arithmetic slips while simplifying; sign mistakes with the “12° less”.
Final Answer:48°