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.

If 21x = 79x, what is the value of x?

There is one four-digit whole number n, such that the last four digits of n2 are the original number n

In the four images below, can you find the odd one out?

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

What happened when the wheel was invented?

Find the Goldfish below the given Image.

What does the below rebus puzzle mean?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

You know three triplets: Frank John and Wayne (need to return your money). Frank always tells the truth while John and Wayne always lie. You meet one of them on the road and can ask him a three-word question.
Which question, will you ask?