Question

the average of mark obtained in an examination by 8 students was 51 & by 9 other students was 68 the average mark of all 17 students was

Answer 1

HYE

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The average of mark obtained in an examination by 8 students was 51

=> x/ 8 = 51

=>x = 51*8

=>x = 408

the average of other 9 = 68

=>x / 9 = 68

=>x = 68*9

=>x =  612

average of all 17

=> 612 + 408 / 9 +8

=> 1020 / 17

=> 60 

avreage of all 17 = 60 marks

hope it helps u ..... :)