A committee is reviewing a total of 20x black-and-white films and 6y color films for a festival. If the committee selects y/x% of the black-and-white films and all of the color films, what fraction R of the selected films are in color?
Choose the most appropriate option:
A) 1 / 130
B) 1 / 5
C) 3 / 13
D) 10 / 13
E) 30 / 31

Rationale: "it ' s y / xpercentnot y / x . if x = 20 and y = 10 . then : 20 x = 400 black - and - white films ; 6 y = 60 color films . y / x % = 10 / 20 % = 0.5 % of the black - and - white films , so 2 black - and - white films and all 60 color films , thus total of 62 films were selected . color films thus compose r = 60 / 62 = 30 / 31 of the selected films . answer : e ."
Answer: E