You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

Can you make four (4) nines (9) equal 100?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?

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?

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

What breaks yet never falls, and what falls yet never breaks?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?