Why Wine Glass Stem is so long?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

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

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

What seven-letter word has hundreds of letters in it?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Can you find a five letter word that is left with only two letters if one is removed?

How many triangles can you count in the figure given?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

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?