If eleven plus two equals one, what does nine plus five equal?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

What is the largest number you can write with just 3 digits?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

Detective Rockford was jogging near the beach at 4:30 am.
He hears a sound near the shack "No Michael, Please Do not shoot me".
Next instance he heard the sound of gunfire. Rockford rushes to the shack where he finds women lying dead and a gun in close proximity of three "Doctore Lawyer and a Teacher".

Rockford immediately knew that the Lawyer has committed the crime. How?

Imagine you are in a room with no windows or doors. How will you get out?

Can you make the below equation true by using any three numbers from "1, 3, 5, 7, 9, 11, 13 and 15"?

( ) + ( ) + ( ) = 30