The average (arithmetic mean) of all scores on a certain algebra test was 90. If the average of the 8 male students’ grades was 86, and the average of the female students’ grades was 92, how many female students took the test?	Select the correct option:	A) 8	B) 9	C) 10	D) 11	E) 16
Total Marks of male = M   Total Marks of female = F   Number of males = 8   Number of females = f   Given: (M+F)/(8+f) = 90 -------------1   Also given, M/8 = 86 Thus M = 688--------2   Also, F/f = 92 thus F = 92 F - --------3   Put 2 and 3 in 1: we get   (688+92f)/(8+f) = 90   solving this we get f = 16   Ans: 16
<result>E</result>
The average (arithmetic mean) of all scores on a certain algebra test was 90. If the average of the 8 male students’ grades was 86, and the average of the female students’ grades was 92, how many female students took the test?