Find the next number in the sequence

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

A mad serial killer kidnaps people and forces them to play the game of 2 pills with them, In this game, there are pills in the table and one of them is normal pill while the other one is deadly poisonous.
The victim will choose one pill and the killer will pick the other pill and both simultaneously will swallow the pill with water.
victim dies every time.

One day the serial killer kidnaps the Joseph and forces him to play the same game with him.

Joseph solves the mystery of the two pills and remains alive.

Explain?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

Two friends were betting. One said to the other, "The coin will be flipped twenty times and each time the coin lands on the head, I will give you $2 and each time it lands on the tale, you will give me $3." After flipping the coin twenty times not a single penny was exchanged among them.

How many times did the coin land on heads?

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

In the image given, you can find several triangles. Can you count them all?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?