What does below rebus means ?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

There was a minor accident with a doctor's son but the doctor noticed no major injury. After the treatment, the father of that doctors son is sitting with the son of the doctor without the doctor being in the room.

How can this be possible?

Suppose you are sitting in an interview and the interviewee asks you an aptitude question.

You have three buckets with a capacity of 4 litres, 8 litres and 10 litres and you have a large tank of water. Now you have to measure 3 litres of water precisely using those buckets. How will you do it?

I guess 76.8% of readers will like this riddle.

What's the least number of people should read this post?