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?  Choose the correct choice from the following choices.
A) 1540
B) 2314
C) 5420
D) 1240
E) 4512

Rationale: "we must place all these books as under : xexex … . xex there are 21 books on english , 19 books on hindi 19 places out of 22 can be chosen 22 c 19 = 22 c 3 = 1540 ways ans : a"
Answer: A