In how may ways can 15 identical books of mathematics and 12 identical books of physics be placed in a row on a shelf so that tow books of physics may not be together ?

In how many ways can 19 indentical books on English and 17 identical books on Hindi be placed in a row on a shelf so that two books on Hindi may not be together ?

In how many ways can 10 books on English and 8 books on physics be placed in a row on a shelf so that two books on physics may not be together?

In how many ways can 10 identical shirts and 7 identical trousers be placed in a row on a shelf so that two trousers may not be together ?

In how many ways can 10 identical shirts and 7 identical trousers be placed in a row on a shelf so that two trousers may not be together ?

In how many ways can 21 books on English and 19 books on Hindi be placed in a row on a shelf so that two books on Hindi may not be together? (A) 770 (B) 385 (C) 1540 (D) 399

In how many ways can 21 books on English and 19 books on Hindi be placed in a row on a shelf so that two books on Hindi may not be together? (A) 770 (B) 385 (C) 1540 (D) 399

In how many ways can 21 identical English and 19 identical Hindi books be placed in a row so that no two Hindi books are together?

In how many ways can 3 books on Hindi and 3 books on English be arranged in a row on a shelf, so that not all the Hindi books are together ?