Marcela, Karla, Isabel, and Viviana all got their math tests back. The average of Marcela, Karla, and Isabel's grades was an 85%. The average of Karla, Isabel, and Viviana's grades was a 78%. If Viviana got a 75%, what did Marcela get?  Choose the correct answer.
A) 90% B) 92% C) 96% D) 88% E) 98%
Solution: Average grade for Marcela, Karla, and Isabel = 85%   Total grade points= 3*85= 
<gadget id="calculator">3*85</gadget>
<output>255</output>
255   Average grade for Karla, Isabel and Viviana= 78%   Total grade points = 3*78= 
<gadget id="calculator">3*78</gadget>
<output>234</output>
234   Viviana got a 75%.   Now,   (Marcela+Karla+Isabel) - (Karla+Isabel+Viviana)= 255-234   Marcela-Viviana = 21   Marcela's score= Viviana's + 21 = 96%   Answer: Option 96%
<result>C</result>
Marcela, Karla, Isabel, and Viviana all got their math tests back. The average of Marcela, Karla, and Isabel's grades was an 85%. The average of Karla, Isabel, and Viviana's grades was a 78%. If Viviana got a 75%, what did Marcela get?