Find the next number in the sequence

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

I have Rs.50 and I spend it in the way as below.

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

Bay of Bengal is in which state?

What has many keys but can’t open a single lock?

I inserted a coin in a bottle and closed its mouth with the help of a cork. Now, I was able to take the coin out from the bottle without taking out the cork or breaking the bottle. Can you tell me how I did it?

I am an odd number. Take away a letter and I become even. What number am I?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

In an office's desk, you find a unique method that shows the current day of the month. Two numbered cubes are used to depict the current date.

Can you find out the numbers on both the cubes so that each date can be mentioned using them?

Please note that you have to use both the cubes to display any date. Thus the 1st day must be represented by 01 and so on.