Replace the question mark with the number below given a simple math problem.

Why is the Hole below a Lock?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

People make me, save me, change me, raise me. What am I?

John was drowned by he was not wet. How?

Something Extraordinary happened on May 6th 19778 at 12:34am what was that?

What does the below rebus puzzle mean?

Find the number of squares in the below-given picture.

John: "Hi Teacher, What is your favourite movie ?".
Chemistry Teacher: "Indium Cerium Platinum Iodine Oxygen Nitrogen".
Ten seconds later... John replied I got it.

Do you?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?