Area is Perimeter

The value of a square's perimeter in inches is the same as the value of its area in square inches. What is the length of it's side?

More Odd Numbers

The sum of a sequence of odd numbers is always divisible by half of the sum of the first and last odd numbers in the sequence. For example, 7 + 9 + 11 + 13 is divisible by ½(7 + 13), and 3 + 5 + 7 + 9 + 11 is divisible by ½(3 + 11). Why?

Russian Mathematicians Again

"Well," said Pavel. "I have two sons closer to one another in age than your two girls, though still some years apart. It is, perhaps, a coincidence that the product of their ages is exactly six times the sum."
"Ah," said Grigori. "Thank you for letting me know their ages."
How old are Pavel's sons?

Russian Mathematicians

Two Russian mathematicians, Pavel and Grigori met at a conference in Vienna where the following conversation ensued:
Pavel: Grigori! It's been such a long time. How are you?
Grigori: Fine, Pavel. And you? I hope you are well.
Pavel: Indeed, I am. It must be fifteen years. You have children now, I believe.
Grigori: Yes two darling girls.
Pavel: And how old are they?
Grigori: Well, it's curious. The product of their ages this year is just three times the sum.
Pavel: I'm sorry, Grigori, but I still can't work out their ages.
Grigori: Of course. I forgot to tell you how excited little Nikki was when Pavla was born.
Pavel then knew the ages of the two girls. What are they? How old was Nikki when Pavla was born?