What is wrong in the below Picture?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

Can you find the key in the picture below?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

One day, I thought of ways that can be used for creating a palindrome. So I decided that I will turn into a larger number by adding the reversed digits to the original number and keep doing it till I finally obtained a palindrome.

I am not sure if this process will always result in a palindrome eventually but I was able to produce a four-digit palindrome. Can you guess my starting number?

"That Restaurant always remains crowded. This is the reason why nobody goes there".

Can you find a flaw in this statement?

How can you tell a raw egg from a hard-boiled egg?

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?

In a family supper, a grandfather, a grandmother, two fathers, two mothers, four children, three grandchildren, one brother, two sisters, two sons, two daughters, one daughter-in-law, and one mother-in-law need to sit at a table.

There are only seven chairs available at the place. How many more chairs do they have to borrow so that everyone can sit down together for the suppers if everybody requires a separate chair?