Which number should replace the question mark?

Can you find out which options fits best with the missing column?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

Can you find the dog hidden in a group of pandas?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

A Child was born in Lahore, Pakistan.

Still child is not a Pakistani citizen.why ?

One evening there was a murder in the home of a married couple, their son and daughter. One of these four people murdered one of the others. One of the members of the family witnessed the crime.

The other one helped the murderer.

These are the things we know for sure:

1. The witness and the one who helped the murderer were not of the same sex.

2. The oldest person and the witness were not of the same sex.

3. The youngest person and the victim were not of the same sex.

4. The one who helped the murderer was older than the victim.

5. The father was the oldest member of the family.

6. The murderer was not the youngest member of the family.

Who was the murderer?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

Can you replace the question mark with the correct number in the below table sequence?