The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Using eight eights and addition only, can you make 1000?

Which number should replace the question mark?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

What goes up but never comes down?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

A pregnant woman is preparing to name her seventh child. Her children's names so far are Dominique, Regis, Michelle, Fawn, Sophie, and Lara. What will she name her next child -- Jessica, Katie, Abby or Tilly?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?