Can anyone tell me a word in the English dictionary which has a silent 'z'?

What does this rebus mean?

O
N
C
E
TIME

I travel all around the world but always stay in the corner. What am I?

Which is Odd One Out and why?

4377

3954

9862

8454

9831

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?

Make a sentence consisting of three words that have the whole alphabet.

What you cannot hold but it is yours?

Can you solve below mathematical equation?

2^1234 - 2^1233

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

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?