If 15 students in a class average 70% on an exam and 10 students average 95% on the same exam, what is the average in percent for all 25 students? Pick:
A) 77%
B) 78%
C) 79%
D) 80%
E) 81%
(15*70 + 10*95) / 25= 
<gadget id="calculator">(15*70 + 10*95) / 25</gadget>
<output>80</output>
80%   The answer is 80%.
<result>D</result>
If 15 students in a class average 70% on an exam and 10 students average 95% on the same exam, what is the average in percent for all 25 students?