What does this mathematical rebus means ?

A man died, leaving $10,000,000 for his widow, 5 sons and 4 daughters. Each daughter received an equal amount, each son received twice as much as a daughter, and the widow received three times as much as a son.

How much did the widow receive?

I have no life, but I can die. What am I?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

Can you solve the maths in the below-given picture equation?

No matter how little or how much you use me, you change me every month. What am I?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?

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

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.