Question

the number of students in 3 sections A,B and C of class 6 in a school are 30,35 and 40. find the minimum number of books required for the class library for equal distribution in section A,B and C.
 

Answer 1

Let  A = 30      B = 35      C = 40

Assume that all students do not go to class library at the same time. At a time either section A or section B or section c visit the library and read the books.

Find the maximum of A, B and C that is greatest integer of 30, 35 and 40.
largest value is 40.
If 40 books are kept in the library, every student in section A can get one book when section A goes to library.  Same way every student in section B gets oone book when sectoion B visits library.  Same for section C.

Answer 2

do LCM of the 30,35 and 40
so LCM = 840 books