Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Move four matchsticks to the below square to form three squares?

What month of the year has 28 days?

Count the number of triangles in the given picture.

Replace the question mark with the correct number in below Picture:

The peacock is a bird that does not lay eggs. How do they get baby peacocks?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

What is full of holes but still holds water?

A convention is held where all the big logicians are summoned. The master places a band on everyone's forehead. Now all of them can see others bands but can't see his own. Then they are told that there are different colours of bands. All the logicians sit in circle and they are further explained that a bell will ring at regular intervals. The moment when a logician knew the colour of band on his forehead, he will leave at the next bell. If anyone leaves at the wrong bell, he will be disqualified.

The master assures the logicians that the puzzle will not be impossible for anyone of them. How will the logicians manage ?