Book Maths Puzzle

There are 10 different books and 20 copies of each book in a library. In how many ways can one or more than one book be selected?

Read Solution (Total 1)

Number of ways in which one or more objects can be selected out of S1 a like
objects of one kind, S2 alike objects of second kind , S3 a like objects of third
kind and so on ... Sn alike objects of nth kind
= (S1 + 1) (S2 + 1)(S3 + 1)...(Sn + 1) - 1

There are 10 different books.
Each book has 20 copies and all the copies of each particular book can be
considered as identical.
Hence, required number of ways
=[(20+1)(20+1)⋯(10 times)]–1=[21×21×⋯(10 times)]–1=2110−1
so that the answer is 2110−12110−1
5 years agoHelpfull: Yes(1) No(2)

Book Other Question

A box contains 4 different black balls, 3 different red balls and 5 different blue balls. In how many ways can the balls be selected if every selection must have at least 1 black ball and one red ball? In how many ways can 4 different balls be distributed among 5 different boxes when any box can have any number of balls?