Age problem

Algebra Level 2

In 1864, Augustus de Morgan, a famous mathematician wrote:

\quad \quad "At some point in my life the square of my age was the same as the year."

What year was he born?

Note: The age of verified oldest person is 122.


The answer is 1806.

A Former Brilliant Member by A Former Brilliant Member

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

The square of 43 is the only feasible square in the 1800's. Since that's 1849 the answer is 1806.

1 Helpful 0 Interesting 0 Brilliant 0 Confused
Munem Shahriar
Oct 5, 2017

4 2 2 = 1764 42^2=1764

If he was 42 in 1764, he would have been born in 1764 − 42 = 1722. 1764 - 42 = 1722. As he wrote it in 1864 , 1864, he would have been 1864 − 1722 = 142 1864 - 1722 = 142 years old at the time!! Which is impossible.

4 3 2 = 1849 43^2=1849

If he was 43 in 1849, he would have been born in 1849 − 42 = 1806 , 1849 - 42 = 1806, making him 1864 − 1806 = 58 1864 - 1806 = 58 years old when he wrote the statement.

Augustus De Morgan must have been born in 1806.

0 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...