Answer:
20/100 x 50 is 10
10% would be 10/100 is fraction form
I want to help you on the first thing you said,
so always consider a percent as a fraction but there denominator is ALWAYS 100 (a way to remember that is that the word "cent" means 100). The word "of" means multiplication so that means your multiplying it with 50 and just do the multiplication.
I'm really hoping you understand!