Can you find the key in the picture below?

Count the number of triangles in the below picture?

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

which number am I?

A man is looking at a photograph of someone. His friend asks who it is. The man replies, “Brothers and sisters, I have none. But that man’s father is my father’s son.” Who was in the photograph?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

2 ladies and 2 girls need to cross a river in a boat big enough for 1 LADY or 2 girls. How do they do it?

I cannot talk, but I always reply when spoken to. What am I?

What am I?

A tourist visits a small town for his research. While in the town, he decides to get a haircut. Since the town is quite small, there are only two barbers in the town � one on the North Street and one on the South Street. The barbershop on the North Street is a mess and the barber has a weird and pathetic haircut. While the barbershop at the South Street is pretty tidy and the barber as well has an impressive haircut.

Which barbershop will the tourist visit for his haircut and why?