Find the next number in the sequence

5 12 24 36 ?

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

John leaves home and then he takes three right turns. John wants to return to home but he was scared of Jacob, who is wearing a mask.

What is John Situation ?

John was writing his first book. After saving the document, he locked his laptop with a password and mentioned some phrases for the hint box.

A friend of his tried opening his laptop but found out that it was password protected. Following is the hint that appeared.
1 mobile 3 books 2 roars 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches.

Can you help him in cracking the password?

Count the number of triangles in the given picture.

There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

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?

What is the largest number you can write with just 3 digits?

Can you count the number of triangles in the given figure?