In the AMS library, there are 8 books by Stephen Covey and 1 book by Vinay Singh in shelf A. At the Same time, there are 5 books by Stephen Covey in shelf B. One book is moved from shelf A to shelf B. A student picks up a book from shelf B. Find the probability that the book by Vinay Singh.
option
(a) 1/3
(b) 8/9
(c) 3/4
(d) 5/9

• i thnk options are incorrect please chk it...because 1/54 will be the ryt ans..to move books from A to B the probability iz 1/9 and selecting one from B is 1/6 as both events are necessry to take place so 1/9 *1/6=1/54..correct me if it z wrong
• 10 years agoHelpfull: Yes(33) No(4)
• question has three part
  1.is still in shelf A.
  ans wud be 8/9...........exp:8/9*6/6=8/9
  2.is in shelf B
  ans wud be 5/54....exp:1/9*5/6=5/54
  3.is taken by student
  ans wud be 1/54..exp:1/9*1/6=1/54.refer arun sharma for clarity of ques..page no. 575
• 10 years agoHelpfull: Yes(17) No(3)
• ans= prob
  1/3
• 10 years agoHelpfull: Yes(4) No(8)
• This question has 3 parts:-
  (1) The book by Vinay Singh is still in shelf A.
  In this case, the book by vinay singh is still in shelf A that means book by Stephen Covey will be transfred from shelf A to shelf B.........that is
  probability = book by Stephen Covey / total books
  and hence probability = 8/9
  
  (2) The book selected by Vinay singh is in shelf B.
  In this case, book selected by vinay singh is in shelf B, and that means that book by vinay singh will be transffred from shelf A to B...and also after the transfer that book is still in shelf B i.e. the student does not pick that book.
  
  probability = probability of book tranfered is by vinay singh * probility of that book not picked by student
  
  hence ans = 1/9 * 5/6(student picks book by Stephen from shelf B) = 5/54.......Ans
  
  (3) Book by vinay singh is taken by student :-
  in this case,
  probability= book transfered is by vinay singh * that book is picked by student
  = 1/9*1/6 = 1/54.......Ans
  
  
  
  
  
  
  
  
• 8 years agoHelpfull: Yes(4) No(0)
• 1/54 would be the right answer
• 10 years agoHelpfull: Yes(2) No(1)