The sum of the one-third, one-fourth, and one-fifth parts of a number exceeds half the number by 34. Find the number.

Difficulty: Easy

Correct Answer: 120

Explanation:


Introduction:
This is a fractional linear equation in a single variable. We will convert each verbal fraction into an algebraic expression in terms of the unknown number and solve.



Given Data / Assumptions:

  • Let the number be N.
  • (1/3)N + (1/4)N + (1/5)N exceeds (1/2)N by 34.
  • N is real; the equation will produce a clean integer.


Concept / Approach:
Bring all N-terms to one side to isolate the net fraction of N equal to 34. Use a common denominator to combine terms exactly.



Step-by-Step Solution:

(1/3 + 1/4 + 1/5 − 1/2)N = 34.Common denominator 60: (20 + 15 + 12 − 30)/60 = 17/60.(17/60)N = 34 → N = 34 * 60 / 17 = 120.


Verification / Alternative check:
Compute both sides with N = 120: LHS partials = 40 + 30 + 24 = 94; half of N = 60; 94 exceeds 60 by 34, correct.



Why Other Options Are Wrong:
60, 30, 90 do not satisfy the equation; “None of these” is unnecessary because a valid integer solution exists.



Common Pitfalls:
Arithmetic with fractions, especially signs when moving 1/2N to the left; ensure exact common denominator.



Final Answer:
120

More Questions from Linear Equation

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion