Math CentralQuandaries & Queries


Question from rachel, a student:

you probably know someone who will x years old in the year x squared. When was that person born?

Hi Rachel,

I like his problem because there is nothing to memorize, no formulas to manipulate and no rule to follow. All you have to work with is your ingenuity (and maybe a calculator).

Certainly this person is not a child or teenager. For example 152 = 225 so someone who was 15 in the year 225 lived about 1800 years ago. I am 68 years old but I doubt I will be around in the year 682 = 4624. Even someone who is 50 years old probably won't be around in the year 502 = 2500.

Find a number x so that x2 is a year when you will most likely be alive. Do you know someone who is x years old? When were they born?


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