Find the next number in the sequence

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

10+10 and 11+11 can give you the same answer.

Explain how?

In the attached figure, you can see a chessboard and two rooks placed on the chess board. What you have to find is the number of squares that do not contain the rooks. How many are there?

A bridge is about to collapse. There are four people P, Q, R and S on one of the sides. Before the bridge collapses, they want to cross it. Now since the bridge is too weak, it can only stand the weight of two people at a time. Also, it is night time and nothing is visible. They have just one torch with them.

Now P takes one minute to cross the bridge, Q takes two minutes to cross, R takes five minutes to cross and S takes ten minutes to cross.

The bridge will collapse in seventeen minutes. How will they be able to cross the bridge before it collapses?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

How can you make a TV, a bed, a dog, and a car liquid?

It is raining today at 11:59 am. What is the probability of sunny weather after 72 hours?

What number do you get when you multiply all of the numbers on a telephone's number pad?