what does this picture(rebus) riddle means ?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

What is the word or phrase below?
R | E | A | D

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

A man was just doing his job when his suit was torn. Why did he die three minutes later?

It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

It is an eleven letter word.
The first, second, third and fourth letters form a banquet's name.
The fifth, sixth and seventh letters form a car's name.
The eighth, ninth, tenth and eleventh letters form a mode of transport.

Can you identify what word it is?

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

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?