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

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

You have $100 with you and you have to buy 100 balls with it. 100 is the exact figure and you can't go below or above the numbers and you have to use the entire $100. If there is no kind of tax applied how many of each of the following balls will you be able to buy:

Green Balls costing $6
Yellow Balls costing $3
Black Balls costing $0.10

Now, how many of each must you buy to fulfil the condition given?

One night, a woman receives a call from the police. They tell her that her husband was murdered and that she should come to the crime scene as soon as possible. The woman drops the phone, shocked, and drives 20 minutes to the crime scene. As soon as she reaches the crime scene, the police arrest her and she is convicted of murder. How do the police know she committed the crime?

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

I cannot talk, but I always reply when spoken to. What am I?

If you say my name, I will no longer exist. What am I?

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

Today is John's birthday.
A year ago, John had five candles and he lit all the candles except the one at the last.
Now he is going to light all the candles.

How old is John Today?

(He is not five today.....)