If 21x = 79x, what is the value of x?

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?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

No matter how little or how much you use me, you change me every month. What am I?

What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

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

What is it?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

John and Jill are madly in love with each other. To remind Jill of his pure love, John wants to send her a ring by post but in their country where burglary is quite prominent, any package that is not locked comes under the risk of being stolen for the contents.

John and Jill possess many padlocks but neither one of them has the other key.

Can you find a way John can send the ring to Jill safely?