What is the coolest letter in the alphabet?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

What part of Turkey has the most feathers?

There was a strange boy who was born before his father. How can this be possible?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

A thief is convicted in Mexico. He gets the death penalty. The judge allows him to say the last sentence to determine how the penalty will be carried out. If the thief lies, he will be hanged, if he speaks the truth he will be beheaded. The thief tells the last sentence and to everybody's surprise some minutes later he is set free because the judge cannot determine his penalty. What did the thief say?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

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 ?