What always comes into a house through the keyhole?

Can You Find the Missing Zero? A Number Puzzle that Will Trick Your Eyes

Can you decipher the following common phrase?

T M C
A U O
H S M
W T E

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

What is the next number in the series?

15 29 56 108 208 ?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

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?

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _