Can you replace the question mark with the correct number in the below table sequence?

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?

Count the Triangle in the figure given below:

15 caves are arranged in a circle at the temple of doom. One of these caves has the treasure of gems and wealth. Each day the treasure keepers can move the treasure to an adjacent cave or can keep it in the same cave. Every day two treasure seekers visit the place and have enough time to enter any two caves of their choice.

How do the treasure seekers ensure that they find the treasure in the minimum number of possible days?

I shave every day, but my beard stays the same. What am I?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

Which point will the car reach to go out?

I know a nine-letter word having only one vowel.
Do you ?

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?