If a·x = b·y (with a, b ≠ 0), then which relation is correct?
Aptitude
Logarithm
Difficulty: Easy
Choose an option
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Ax : y = b : a
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Bx : y = a : b
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Cx / y = a / b
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Dax / by = 1/ab
Answer
Correct Answer: x : y = b : a
Explanation
Given data
- a·x = b·y, with a and b nonzero.
Concept / Approach
- Simple proportion: if products are equal, variables are in inverse ratio to coefficients.
Step-by-step calculation
a·x = b·y ⇒ divide both sides by a·y: (x / y) = (b / a)Therefore, x : y = b : ax : y = b : a
Verification
Example: let a = 2, b = 3, choose x : y = 3 : 2 ⇒ LHS = 2·3 = 6; RHS = 3·2 = 6.
Common pitfalls
- Writing x : y = a : b (that would imply a·x and b·y are not equal unless a = b).
Final Answer
x : y = b : a