Please help and show work if you can. I’ll give brainliest

Answer:
A=81, B=91.7, C= 76.15
Step-by-step explanation:
A= (82*.15)+(85*.15)+(78*.25)+(75*.15)+(84*.30)
B= (92*.15)+ (88*.15)+(95*.25)+(85*.15)+(94*.30)
C= (74*.15)+ (68*.15)+ (73*.25)+ (82*.15)+ (81*.30)