Can you place six X (crosses) in below board without making three in a row in any way ?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

What is the next number in the series?

15 29 56 108 208 ?

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?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

How many triangles are there on the puzzle below?

Can you find a five letter word that is left with only two letters if one is removed?

After a heavy Thanksgiving meal, the night watchman went to work. In the morning, he told his boss he had dreamed that a saboteur planted a bomb in the factory and that he felt it was a warning. The boss promptly fired him. Worker confused, Why boss fire him?