What is common among 11, 69, and 88?

Why is a river so rich ?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

Usually, a boxing match consists of twelve rounds. In a particular friendly match between two heavyweights, the match was finished in the ninth round itself as one of the boxers knocked out the other one.

But, in that fight, no man threw even a single punch.

How can this be possible?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

Give it food and it will live; give it water and it will die.