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

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

Can you find the 09 errors in the picture below?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

Identify the movie name through below Rebus containing Pi Mouse and coconut tree..

When it's bad luck to meet a black cat?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?