Present ages from future sum – “X” and her grandfather differ by 50 years. Six years from now, their ages will sum to 152. What are their present ages?

Difficulty: Easy

Correct Answer: 45, 95

Explanation:


Introduction / Context:
Two linear relations are provided: a present-time difference and a future-time sum. Solving them together cleanly yields the present ages without trial-and-error.



Given Data / Assumptions:

  • Let x = X’s present age, g = grandfather’s present age.
  • g − x = 50.
  • (x + 6) + (g + 6) = 152 ⇒ x + g = 140.


Concept / Approach:
Solve the simple system: x + g = 140 and g − x = 50. Adding gives 2g = 190 ⇒ g = 95, then x = 45.



Step-by-Step Solution:
x + g = 140.g − x = 50.Add: 2g = 190 ⇒ g = 95.Then x = 140 − 95 = 45.



Verification / Alternative check:
Six years later: 51 + 101 = 152, as required; difference now: 95 − 45 = 50.



Why Other Options Are Wrong:
The other pairs do not simultaneously satisfy both equations.



Common Pitfalls:
Subtracting the equations in the wrong order or misreading “after 6 years” as “in 6 years total.”



Final Answer:
45, 95

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