A student gets an aggregate of 60% marks in five subjects in the ratio 10 : 9 : 8 : 7 : 6. If the passing marks are 50% of the maximum marks and each subject has the same maximum marks, in how many subjects did he pass the examinaiton? Choose the correct option:
A) 2 B) 3 C) 4 D) 5 E) 6
Explanation :   Let the full marks of each subject is 100. So, total marks in 5 subject is 500.   Student gets 60% aggregate marks i.e 60% of 500 = 300.   =&gt; 10x + 9x +8x +7x + 6x = 300   =&gt; 40x = 300.   =&gt; x = 300/40 = 7.5.   Hence,   The marks in first subject = 10x = 7.5 x 10 = 75.   The marks in 2ndsubject = 9x = 7.5 x 9 = 67.5.   The marks in 3rd subject = 8x = 7.5 x 8 = 60.   The marks in 4th subject = 7x = 7.5 x 7 = 52.5.   The marks in 5th subject = 6x = 7.5 x 6 = 45.   Thus , he passed in all 5 subjects.   Answer : 5
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A student gets an aggregate of 60% marks in five subjects in the ratio 10 : 9 : 8 : 7 : 6. If the passing marks are 50% of the maximum marks and each subject has the same maximum marks, in how many subjects did he pass the examinaiton?