Move four matchsticks to the below square to form three squares?

Christina is older than Kareena and Karishma. Katrina is older than Karishma and younger than Kareena. If Kareena has a brother named John, who is older than Christina, who's the youngest?

Can you count the number of triangles in the picture below?

I am the fastest animal but cannot climb the tree. What am I?

81 x 9 = 801. What must you do to make the this equation true?

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?

Complete the table series riddle by finding the number that can replace "??".

Why is it very easy to weigh a fish?

A thief is convicted in Mexico. He gets the death penalty. The judge allows him to say the last sentence to determine how the penalty will be carried out. If the thief lies, he will be hanged, if he speaks the truth he will be beheaded. The thief tells the last sentence and to everybody's surprise some minutes later he is set free because the judge cannot determine his penalty. What did the thief say?

I know a nine-letter word having only one vowel.
Do you ?