Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)

Can you identify the hidden rebus in the image below?

Solve the mathematical equation in the picture below.

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

what does the below rebus mean?

You need to move three matchsticks to form three squares. Can you do it?

What 5-letter word typed in all capital letters can be read the same upside down?

What is the riddle which can be asked all day with a different correct answer each time.