Two fathers and two sons decided to go to a shop and buy some sweets upon reaching. Each of them bought 1 kg of sweet. All of them returned home after some time and found out that they had 3kg of sweets with them.

They did not eat the sweets in the way, nor threw or lose anything. Then, how can this be possible?

If eleven plus two equals one, what does nine plus five equal?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

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

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

I add 5 to 9 and get 2. The answer is correct, so what am I?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

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