There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

What number do you get when you multiply all of the numbers on a telephone's number pad?

Can you find out the total number of triangles in the given figure?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

Can you count the number of squares in the figure below?

If you were to put a coin into an empty bottle and then insert a cork into the neck, how could you remove the coin without taking out the cork or breaking the bottle?

There is a unique number which when multiplied by any number from 1 to 6, we will get the new number that contains the same digits only.

Can you find that number?