Qm
Brainteasers

The person whose age is the square root of the year

numberssquaresagescalendar

A mathematician says: "In a certain year of my life, my age will be exactly the square root of that year." She was born in the twentieth century and is alive now (the 2020s).

In which year was she born, and how old will she be in the special year? Is the answer unique?

Show a hint

Which perfect squares fall within a modern lifetime? Find the square roots of years near the present.

Your answer

Solving needs a free account

Answers, streaks and solutions unlock when you are signed in. Reading the question and the hint stays free.

Create a free accountSign in

Discussion

Sign in to join the discussion · reading is open to everyone

💡 Discussion rules

  1. No full solutions here. Hints and approaches only.
  2. Complexity, edge cases and intuition are the point.
  3. Interview experiences are welcome. Respect your NDAs.

Loading discussion…

Learn the concepts

The theory behind this question.

Adaptive Versus Pre-Committed Weighing StrategiesThe Lost Boarding Pass ProblemAM-GM as a Puzzle ToolAnts on a Pole and Collision ArgumentsThe Arcsine Law: Who Leads a Coin-Flip Race

Related questions

The cannonballs that make a square and a pyramidThree ages that add to 20 and multiply to 240The two-digit number that is the square of its digit sumWriting 100 as a sum of consecutive numbers999 times 999 in your head
All questions →