What is the next number in this matchsticks series riddle?

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 ?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

A bomb exploded in a room full of married couples and no one died. How?

A woman is sitting in her hotel room and hears a knock at the door. She opens the door to see a man whom she’s never met before. He says, “I’m sorry, I have made a mistake, I thought this was my room.” He then goes down the corridor and into the elevator. The woman goes back into her room and calls security. What made the woman so suspicious of the man?

Can you replace the question mark with the correct number?

John buys rice at Rs.60/kg from Britain and then sells them at Rs.5/kg in India. As a result of this, he becomes a millionaire. How come?

What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

Can you find out the number that should replace the question mark with a valid reason?