More Questions from Order of Magnitude

The sum of two numbers, when multiplied by each number separately, produces 2418 and 3666 respectively. Find the absolute difference between the two numbers.

Aptitude Order of Magnitude Difficulty: Medium
Choose an option
  • A
    16
  • B
    21
  • C
    19
  • D
    23
  • E
    None of these

Answer

Correct Answer: 16

Explanation

Introduction:Let the numbers be a and b with sum s = a + b. We are given s * a and s * b; this permits solving for s and then |a − b| without finding a and b individually.

Given Data / Assumptions:

  • s * a = 2418
  • s * b = 3666
  • s = a + b

Concept / Approach:Add the two equations and use s = a + b to solve for s, then use the difference to find |a − b|.

Step-by-Step Solution:s * a + s * b = 2418 + 3666 = 6084s(a + b) = s * s = s^2 = 6084s = sqrt(6084) = 78Compute |a − b| = |(s * b − s * a)| / s = |3666 − 2418| / 78 = 1248 / 78 = 16

Verification / Alternative check:One can set a = 2418/78 and b = 3666/78, then verify the difference is 16.

Why Other Options Are Wrong:21, 19, 23: Do not match the computed difference from the given products.

Common Pitfalls:Forgetting that s^2 = 6084; making arithmetic slips with 1248/78 simplification.

Final Answer:16

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