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

Krish is 45 years old and his mother Crishtina is 73 years old.

Can you find out how many years ago, his mother was three times his age?

Christina is older than Kareena and Karishma. Katrina is older than Karishma and younger than Kareena. If Kareena has a brother named John, who is older than Christina, who's the youngest?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

I’m orange, I wear a green hat and I sound like a parrot. What am I?

Which is the smallest number that you can write using all the vowels exactly once?

When does a USA Potato change its nationality?

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

Be active and find the killer in the picture Riddle below.