What is both possible and impossible at the same time?

Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

Some friends went on a vacation to a resort. It was raining heavily and it kept raining for thirteen days.

When it rained in the morning, the afternoon was beautiful and when it rained in the afternoon, the day was blessed with a clear morning.

Overall, the friends experienced eleven nice mornings and twelve nice afternoons. Can you find out the number of days they spent on vacation?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

Which is heavier: a ton of bricks or a ton of feathers?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

Suppose you are sitting in an interview and the interviewee asks you an aptitude question.

You have three buckets with a capacity of 4 litres, 8 litres and 10 litres and you have a large tank of water. Now you have to measure 3 litres of water precisely using those buckets. How will you do it?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

What goes through cities and fields, but never moves?

Can you decipher the two rows to find the hidden word?