Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

How many words can a quill made with the feather of a pigeon write with a 100ml bottle of black ink?

An ape is trying to climb on a pole that is 60 feet high. Due to the slippery surface, the ape climbs 3 feet in a minute only to slip back 2 feet.

How much time do you think the monkey will take to reach the top of the pole?

What's the only room from which no one can enter or leave

What question can you never answer yes to?

There’s a one-story house in which everything is yellow. Yellow walls, yellow doors, yellow furniture. What colour are the stairs?

You need to remove two matchsticks to make the below equation true. Can you do it ?

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

I can write cow in 13 letters.

Can You?