In the last set of tests, a student scored marks in each of 5 subjects in the ratio 4:5:6:7:8 and got an overall average score of 72%. If a mark of 50% in a subject is a pass and the maximum marks of each subject is the same, how many subjects did the student pass?
Pick one.
A) 1  B) 2  C) 3  D) 4  E) 5
The tests scores are 4k, 5k, 6k, 7k, and 8k.   The sum of the test scores is 30k.   The average test score is 30k/5 = 66. Then k = 11.   The test scores are 44, 55, 66, 77, and 88.   The student passed 4 subjects.   The answer is 4.
<result>D</result>
In the last set of tests, a student scored marks in each of 5 subjects in the ratio 4:5:6:7:8 and got an overall average score of 72%. If a mark of 50% in a subject is a pass and the maximum marks of each subject is the same, how many subjects did the student pass?