The grade point average of the entire class is 90. If the average of one third of the class is 96, what is the average of the rest?  Pick one.
A) 92	B) 89	C) 88	D) 87	E) 86
Let us take number of students on the class as 'x'.   avg grade point = sum of all grade points/x   sum of all grade points = avg grade point*x = 90x   average of one third of the class = 96 = sum of one third grade points of the class/(x/3)   sum of one third grade points of the class = 96*(x/3) = 32x   sum of rest two third grade points of the class = sum of all grade points - sum of one third grade points of the class   sum of rest two third grade points of the class = 90x-32x = 58x   avg of two third of the class 90 -32= 
<gadget id="calculator">90 -32</gadget>
<output>58</output>
58x   avg of two third of the class= sum of rest two third grade points of the class/(x*2/3) = 58x/(2x/3) = 29*3= 
<gadget id="calculator">29*3</gadget>
<output>87</output>
87.   Hence, answer is 87
<result>D</result>
The grade point average of the entire class is 90. If the average of one third of the class is 96, what is the average of the rest?