5 Maths books can be arrange in 5! ways = 5 x 4 x 3 x 2 x l = 120 ways 3 English books can be arrange in 3! ways = 3 x 2 x 1 = 6 ways 3 Biology books can be arrange in 3! ways = 3 x 2 x 1 = 6 ways Now, 3 different subject books can be arrange in 3! ways = 3 x 2 = 6 ways Hence, total number of arrangement = 120 x 6 x 6 x 6 = 25920