There are 5 maths, 4 science and 4 English books to be arranged on a shelf. Books of same subjects are together. Find the number of ways if books of same subject are different.
1
5! × 4! × 4! × 3!
2
5! × 4! × 4!
3
5! × 4!× 3!
4
5! × 4! × 3! × 2!
5
none of these