Question

WHAT IS THE LOGIC BEHIND THIS TRICK?
Ask somebody to pick a number.
Tell them to double that number.
Then, ask them to add 9.
Subtract 3.
Divide by 2.
And finally, to subtract the original number.

NOTE: ANYBODY WHO GIVES AN INVALID ANSWER IS GOING TO BE REPORTED

Answer 1

Answer:

Let the number be x.

Then, double the number -> 2x

add 9 -> 2x + 9

subtract 3 -> 2x + 6

divide by 2 -> x + 3

subtract original number -> x + 3 - x = 3

answer always turns out to be 3