Five different books (A, B, C, D and E) are to be arranged on a shelf. Books C,D and E are to be arranged first and second starting from the right of the shelf. The number of different orders in which books A, B and may be arranged is	Select:	A) 1!	B) 2!	C) 5!	D) 15!	E) 24!
Solution   Since books C,D and E are arranged first and second, only books A and B will change order. Therefore it an arrangement problem involving 2 items and the number of different order is given by   2!   Answer 2!
<result>B</result>
Five different books (A, B, C, D and E) are to be arranged on a shelf. Books C,D and E are to be arranged first and second starting from the right of the shelf. The number of different orders in which books A, B and may be arranged is