Answer:
The original price of the dvd is 20 dollars.
Explanation:
I know this because 50% of something is the equivalent of saying it is half (or in this case, half off), so all you have to do is find the number that reverses the division, meaning instead of dividing by two, you'd use the opposite operation. you would multiply 10 by 2, which is the opposite of diving by 2, to then get 10 time 2 = 20.
So, your answer is $20
Hope this helps! :)