Which function would be used to remove a section of text from a document?

An english teacher would like to divide 8 boys and 10 girls into groups, each with the same combination of boys and girls and nobody left out. what is the greatest number of groups that can be formed?

How would you cite different books by the same author on the works cited page? moore, jack h. folk songs and ballads. salem: poetry press, 1999. print. moore, jack h. ballads in poetry – a critical review. dallas: garden books, 1962. print. moore, jack h. folk songs and ballads. salem: poetry press, 1999. print. –––. ballads in poetry – a critical review. dallas: garden books, 1962. print. moore, jack h. ballads in poetry – a critical review. dallas: garden books, 1962. print. moore, jack h. folk songs and ballads. salem: poetry press, 1999. print. moore, jack h. ballads in poetry – a critical review. dallas: garden books, 1962. print. –––. folk songs and ballads. salem: poetry press, 1999. print.

Can someone work out the answer as it comes up in one of my computer science exams and i don't understand the cryptovariables