What brings you down but never up?

What does the below rebus puzzle mean?

Do you know who was buried in John's tomb?

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 ?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

If you were to put a coin into an empty bottle and then insert a cork into the neck, how could you remove the coin without taking out the cork or breaking the bottle?

Can you place six X (crosses) in below board without making three in a row in any way ?

How far can you walk into the woods?

What is next number in the pattern below:

131 517 192 123 ?

Can you count the number of lines in the below picture?