It belongs to you, but other people use it more than you do. What is it?

Which number should replace the question mark?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Can you write down eight eights so that they add up to one thousand?

Which word is least like the others? Third, fourth, fifth, sixth, seventh, eighth, ninth?

A thief enters a store and threatens the clerk, forcing her to open the safe. The clerk says, “The code for the safe is different every day, and if you hurt me you’ll never get the code.” But the thief manages to guess the code on his own. How did he do it?

What part of the chicken has the most feathers?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?