The centre of the third figure is empty. What digit should fit inside?

What number should come in place of the question mark below?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

There's a day, that comes around once a year.
To celebrate the man, you hold dear.
He gave you life, love and will pick you up if you fall.
When it comes to guys like him, He's the best of all.
Who is he?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

What 5-letter word typed in all capital letters can be read the same upside down?

Rearrange the letters in "new door" to make one word.