How many words can a pen with half refill write?

What does this mean?

CCCCCCC

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

John was a very careless driver, so his owner Jacob gave him an offer that he will get an incentive of Rs.30 for every bottle box he delivered without breaking it and he will be charged Rs.90 for every bottle box he broke. Jacob gave John 100 bottles-box to deliver. After delivery, Jacob paid John Rs.2400. How many bottles-box did John break?

Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

If,
9 * 8 * 7 = 65
8 * 7 * 6 = 50
7 * 6 * 5 = 37

Find
6 * 5 * 4 = ?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?