Can you count the number of triangles in the given figure?

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

which number am I?

Can you find out which options fits best with the missing column?

Three people are in a room. Ronni looks at the Nile. The Nile looks at Senthil. Ronni is married but Senthil is not married. At any point, is a married person looking at an unmarried person? Yes, No or Cannot be determined.

Astrology starts with the alphabet A, Biology starts with B, Psychology with P and Limnology with L.

Can you find an "ology" that begins with a P?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

What do you see in the image 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?