Can you solve the photo plexer logic ?

Once while in his court, King Akbar asked Birbal to write something on a wall that makes one sad when read in good times and makes one happy when read in sad times.

He took only a few moment and wrote something that fit the requirements. What did he write?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

What is more useful when it is broken?

What kind of tree can you carry in your hand?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

John was born on March 5, 1970, in Delhi, India. Jacob was born 25 days before John. The year when they took birth, Republic Day fell on Monday.

Can you find out on what day was Jacob born?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

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?

10+10 and 11+11 can give you the same answer.

Explain how?