A bakery wishes to display seven of its 14 types of cake in a row in its shop window. There are six types of sponge cake, five types of cheesecake and three types of fruitcake. Find the number of possible displays that can be made if the bakery places:

a. A sponge cake at each end of the row and includes no fruitcakes in the display

b. A fruitcake at one end of the row with sponge cakes and cheesecakes placed alternately in the remainder of the row.