If eleven plus two equals one, what does nine plus five equal?

I’m orange, I wear a green hat and I sound like a parrot. What am I?

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

We have two identical balls in terms of diameter and weight. However, one of them is solid and the other is hollow.

Without knocking the ball, can you find the solid ball?

What makes this number unique: 8,549,176,320?

What does below rebus means ?

There are three cows, two dogs, and one cat: How many legs do you have?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?