When we see 2 but call 10?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Before Mount Everest was discovered, what was the highest mountain in the world?

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

What has a bottom at the top?

A donkey is behind another donkey
I'm behind that second donkey
But there is a whole nation behind me

It is a murder you can describe in a word.

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?

What has many keys but can’t open a single lock?

On a charity event in Russia, Murray beat Djokovic by winning six games and losing three games.
Note: There is a total of 5 service breaks(one who serve lost the game).
Who served first, Djokovic or Murray?