What is the word or phrase?

Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

There is so small cabin inside a deep forest.
All the forest burned out to worst possible but the inside of the cabin is still the same.
However all the person inside the cabin die.

How come ?

What breaks yet never falls, and what falls yet never breaks?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

Which is faster, Heat or Cold ? Explain.

How many triangles are there on the puzzle below?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?