Question

Jim has 5 computer science books and 3 math books. he has room to arrange four of them on a shelf. he wants at least two computer science books and at least one math book, and he wants to keep the computer science books and the math books together. in how many ways can he arrange the books?

Answer 1

Answer: There are 60 different ways that he can arrange the books.

Explanation:

Since we have given that

Number of computer science books = 5

Number of math books = 3

Number of books selected = 4

Atleast Number of computer science = 2

Atleast number of math book = 1

According to question, he wants at least two computer science books and at least one math book, and he wants to keep the computer science books and the math books together.

So, Number of different ways that he can arrange the books is given by

`^5C_2* ^3C_2+^5C_3* ^3C_1\\\\=30+30\\\\=60`

Hence, there are 60 different ways that he can arrange the books.