Five different books (A, B, C, D and E) are to be arranged on a shelf. Books C and D 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 E may be arranged is  Pick one:  A) 5!  B) 3!  C) 2!  D) 3! * 2!  E) None
Solution   Since books C and D are arranged first and second, only books A, B and E will change order. Therefore it an arrangement problem involving 3 items and the number of different order is given by   3!   Answer 3!
<result>B</result>
Five different books (A, B, C, D and E) are to be arranged on a shelf. Books C and D 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 E may be arranged is