What does this rebus mean?

O
N
C
E
TIME

Spot the cat in the picture below

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

Can you identify the Oscar-winning movie from the rebus below?

Complete the table series riddle by finding the number that can replace "??".

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

What has 13 hearts but no other organs?

A man wants to cross the pit of fire which is 25 feet in length and he has 2 planks(fire resistant) 19 feet in length. How can he cross the pit of fire alive?

Once upon a time, there was a castle on a square island. The entire island was surrounded by a 14m wide trench. The Romans had wanted to invade the castle and had brought a few wooden planks along with them to facilitate themselves in crossing the moat. The planks were however found to be only 13m long.

The Romans still managed to cross the trench. How did they do it?

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