Answer:
x = 15, y = 5
Explanation:
total score of A = 6x
total score of B = 25*8 = 200
total score of C = 20y
(6x+200)/(x+25)=7.25
6x+200 = 7.25x+181.25
18.75 = 1.25x
x = 15
and
(6x+200+20y)/(x+25+20) = (6x+200+20y)/(x+45) = 6.5
plug in x
(290+20y)/60 = 6.5
290 + 20y = 390
20y = 100
y = 5