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?	Pick.
A) 3990	B) 1540	C) 1995	D) 3672	E) 2314
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 22C19=22C3=1540 ways   ANSWER 1540 1540
<result>B</result>
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?