If 21x = 79x, what is the value of x?

A kind heart person buy packed food at 3$/packet from United states and sells them at 1$/packet at Africa. After some time he becomes a millionaire.

How come the guy become millionaire ?

Can you find out the remainder when 3^300 is divided by 5?

A man lives on the fifteenth floor of an apartment building. Every morning he takes the elevator down to the lobby and leaves the building. In the evening, he gets into the elevator, and, if there is someone else in the elevator, or if it was raining that day, he goes back to his floor directly. Otherwise, he goes to the tenth floor and walks up five flights of stairs to his apartment. Can you explain why he does this?

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?

how come the second man dies?

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

Can you name an animal whose killing cannot be performed without spilling your own blood?

Can you count the number of triangles in the given figure?

There is a place where if I stand up straight, I will still be considered sideways.