Using Only Five 5's and any mathematical operator make sum as 37

I have Rs.50 and I spend it in the way as below.

Buy me, smell me or deliver me, I do not change.

Who am I?

I have some blue and red sock in my drawer. I have a total of 4 socks. I pick 2 socks and the chance that I get a pair of red socks is 1/2.

What is the chance of picking a pair of blue socks?

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

John is 45 years older than his son Jacob. If you find similarities between their ages, both of their ages contain prime numbers as the digits. Also, John's age is the reverse of Jacob's age.

Can you find their ages?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

Which is the correct shadow of the bird?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?