5 votes 5 votes 46) A shelf holds 12 books in a row. How many ways are there to choose five books so that no two adjacent books are chosen? Combinatory kenneth-rosen discrete-mathematics combinatory + – sushmita asked Apr 21, 2017 • edited Mar 6, 2019 by Pooja Khatri sushmita 2.5k views answer comment Share Follow See all 8 Comments See all 8 8 Comments reply Show 5 previous comments Devshree Dubey commented Apr 21, 2017 reply Follow Share @Sonam, how with remaining 7 books it cud mean 8 places??Can u please elaborate on ur explanation part?? 0 votes 0 votes sandeep007734 commented Apr 21, 2017 reply Follow Share If you have two books, then there are 3 places. o | o | o here "|" marks the books and "o" empty spaces. By the same logic, when you have 7 books there are 8 empty spaces. 1 votes 1 votes sushmita commented Apr 21, 2017 reply Follow Share Yes Sonam it's 56. Thanx a lot. Nice analogy used. 1 votes 1 votes Please log in or register to add a comment.
Best answer 10 votes 10 votes ans should be 56 . minal answered Apr 21, 2017 • selected Apr 22, 2017 by srestha minal comment Share Follow See all 6 Comments See all 6 6 Comments reply Show 3 previous comments s9k96 commented Apr 21, 2017 reply Follow Share Cant books shuffle around ? they should be identical i think. 1 votes 1 votes Devshree Dubey commented Apr 21, 2017 reply Follow Share @Sonam, I now got ur point. Actually I was taking 8 places to be books and getting confused. So now it is clear. In this way d total shall be 12. Actually u've made d question easier and simplified it with a little bit change. Thanks a lot. :) 1 votes 1 votes minal commented Apr 21, 2017 reply Follow Share @s9k96 , i think we have to select so it mean lot rt .. 1 votes 1 votes Please log in or register to add a comment.
