I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

I don't get anymore wetter, no matter how much rain falls on me.

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

French Police inspects a room where there are no windows, no doors, no tables and is almost empty expect there is just a puddle of water. They found a dead man who obviously hung herself from the ceiling, but they are not able to figure out how this had happened.

John and Jacob entered the crime scene and easily able to solve the case.

How did the man die?

In my garden, I have many trees but only one of them is the mango tree. In these mango trees, there are some mangoes(as expected).

But after a strong wind, there are neither mangoes on the tree nor on the ground. Explain?

Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?