In hw many ways can 21 eng buks n 19 Hindi buks b placed so that two buks on Hindi may not b together?

• We can arrange in this way...
  
  -E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-
  
  Hindi book should be precede nd followed by an English book...
  English books can be arranged among themselves in => 21! ways...
  Hindi books can be arranged among themselves in => 19! ways...
  There are 22 spaces... We have to place 9 hindi books there...
  So 22C19 ways...
  
  Totally 22C19 * 21! * 19! ways =>
  
  Ans : 1540 * 21! * 19!
• 10 years agoHelpfull: Yes(11) No(0)