There are three students and three teachers among A, B, C, D, E and F. Each of these has taken three tests among the tests 1 through 6. Among which, two tests are only for students, two tests are only for teachers and two tests can be taken by both teachers and students. No two of them has taken the same set of tests.

(1) No test is taken by both A and D. Only test 6 is taken by both E and F.

(2) Test 5 is only for teachers while test 4 is only for students.

(3) E took the tests 1, 4 and 6 while A did not take test 5.

(4) Only test 3 is taken by both A and B.

13. What are the tests taken by D?

(A) 2,5,3

(B) 2,5,6

(C) 4, 1,6

(D) 5, 1,6

14. Which of the following tests are only for students?

(A) 1,2

(B) 4, 1

(C) 5,6

(D) 2,5

15. How many persons took the test 6?

(A) 3

(B) 2

(C) 4

(D) Cannot be determined

16. Which of the following test is taken by C?

(A) 4

(B) 5

(C) 2

(D) 3