Which number should replace the question mark?

Can you make four (4) nines (9) equal 100?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

If your uncle’s sister is not your aunt, what relation is she to you?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Tell me the Hindi name of a Vegetable which if we remove 1st word will become a precious Stone and by removing the last word it will become a sweet eatable.

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

What does a man do only once in his lifetime, but women do once a year after they are 29?

Can you solve below mathematical equation?

2^1234 - 2^1233