Find the next number in the sequence

1, 2, 6, 21, 88, __?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

What is the longest word in the dictionary?

You are an expert on paranormal activity and have been hired to locate a spirit haunting an old resort hotel. Strong signs indicate that the spirit lies behind one of four doors. The inscriptions on each door read as follows:

Door A: It's behind B or C
Door B: Its behind A or D
Door C: It's in here
Door D: It's not in here

Your psychic powers have told you three of the inscriptions are false, and one is true. Behind which door will you find the spirit?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

You are provided with a grid (as shown in the picture). Can you fill the squares with numbers 1-8 in a manner that none of the two consecutive numbers are placed next to each other in any direction (vertically, horizontally or diagonally?)

If eleven plus two equals one, what does nine plus five equal?

John was running from 40 thieves. John has got 3 gold boxes which weigh as 4kg, 2kg, and 1kg respectively. A witty man asked John to stay with him for seven days in exchange for 1kg gold per day. John needs to stay there for seven days and also do not want to give the witty man any advance. How can John pay for his seven days stay?