The average mark of 10 students is 80%. Later it was found that for one student, instead of 60%, the recorded 90%, by mistake. Now the corrected new percentage?
Choose the correct option:	A) 55	B) 66	C) 77	D) 88	E) 99
lets assume the total marks in the exam per student is 100.   and given that avg mark of 10 student is 80%   so, total mark=80*10= 
<gadget id="calculator">80*10</gadget>
<output>800</output>
800 ;   but instead of 60 mark they take wrong as 90 mark;   so,800-90 + 60=770   this is correct mark of 10 student   and then average of 10 student is =770/10= 
<gadget id="calculator">770/10</gadget>
<output>77</output>
77   ANSWER:77
<result>C</result>
The average mark of 10 students is 80%. Later it was found that for one student, instead of 60%, the recorded 90%, by mistake. Now the corrected new percentage?