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

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

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

Which of the below owl is odd one out?

I am a mother. However, I never give birth.

I am a father. However, I never nurse my children.

Wandering is not possible for me, but standing still happens occurs rarely.

Who am I?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

If,

A = 1

B = 2

C = 3

...

...

Z = 26.

Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.