If 15 students in a class average 70% on an exam and 10 students average 90% on the same exam, what is the average in percent for all 25 students?
Choices.
A) 78%	B) 79%	C) 80%	D) 81%	E) 82%
(15*70 + 10*90) / 25= 
<gadget id="calculator">(15*70 + 10*90) / 25</gadget>
<output>78</output>
78%   The answer is 78%.
<result>A</result>
If 15 students in a class average 70% on an exam and 10 students average 90% on the same exam, what is the average in percent for all 25 students?