What does this Rebus Picture mean?

Your last good ping-pong ball fell into a narrow metal pipe embedded one foot deep in concrete.
How can you get it out undamaged, if all the tools you have are your tennis paddle, shoe laces, and plastic water bottle, which does not fit into the pipe?

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

What is the next shape from answers A, B, C, and D figure?

In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.