A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

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.

Next Number in the Series,

5, 16, 49, 104, ?

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.

What does below pictogram mean?

John went to buy some expensive, foreign chocolates. He only had Rs 100 with him. When he reached the shop, he got out and know that on those chocolates, there was a 15% import duty and 5% VAT.

How much worth chocolate should he buy so that he can accommodate it in Rs 100?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?