Difficulty: Medium
Correct Answer: 3/14
Explanation:
Introduction / Context: Percentage changes to numerator and denominator scale a fraction by separate multipliers. Translate the described changes into factors and solve for the original fraction.
Given Data / Assumptions:
Concept / Approach: Form the equation (3x)/(2.5y) = 9/35. Simplify the coefficient 3/2.5 to 6/5 or 3/(5/2). Solve for x/y and reduce to lowest terms.
Step-by-Step Solution:
(3x)/(2.5y) = 9/35 ⇒ (x/y) = (9/35) * (2.5/3).(2.5/3) = (5/6). So x/y = (9/35) * (5/6) = 45/210 = 3/14.Verification / Alternative check: Starting from 3/14: New value = (3*3)/(14*2.5) = 9/35 as required.
Why Other Options Are Wrong: 3/10, 2/15, 2/7 do not transform to 9/35 under the stated multipliers.
Common Pitfalls: Treating 200% increment as 2x instead of 3x, or 150% increment as 1.5y instead of 2.5y.
Final Answer: 3/14
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