What will be the difference between the marks secured by E and D?

Study the given information carefully and answer the following questions. Seven people – A, D, E, G, H, Q and W are studying in three different classes, Class 5, Class 7 and Class 6. Not more than three people Studying in the same class. They secure different marks in Science viz., 5, 16, 19, 20, 24, 36 and 57 but not necessarily in the same order. The persons who are studying in 6th class secure only even numbered marks and the persons who are studying in 7th class secure only Odd numbered marks. The marks secured by class 5 students are more than that of the marks secured by class 7 students. A Secured less than 30 marks and studies with W. The sum of marks secure by H and W is more than 90 marks. Only Q and D studying in class 7. Q secured more marks than
D. A and E are studying in different class. A secure more marks than G. A and H studying in different class. E and G secure a mark which is a multiple of 4. G and W are studying in the same class. A is junior to H. The mark scored by E is not a multiple of 5.