Since all statements say “can be”, we just need to find one case that is possible for each statement. This is not tough to do as shown below.

p is a prime number. So, p can be 2, 3, 5, 7, 11, 13, .….
q is a composite number. So, q can be 4, 6, 8, 9, 10, .….

Statement 1: p × q can be an odd number, e.g. (3 × 9 = 27). Thus, statement 1 is correct.
Statement 2: q/p can be a prime number, e.g. (4/2 = 2). Thus, statement 2 is correct.
Statement 3: p + q can be a prime number, e.g. (3 + 4 = 7). Thus, statement 3 is correct.

Thus, all the statements 1, 2 and 3 are correct.