(a) In a sweet shop 5 identical packets of toffees, 4 identical packets of fruit gums and 9 identical packets of chocolates are arranged in a line on a shelf. Find the number of different arrangements of the packets that are possible if the packets of chocolates are kept together.

(b) Jessica buys 8 different packets of biscuits. She then chooses 4 of these packets.

1. How many different choices are possible if the order in which Jessica chooses the 4 packets is taken into account?

The 8 packets include 1 packet of chocolate biscuits and 1 packet of custard creams.

2. How many different choices are possible if the order in which Jessica chooses the 4 packets is taken into account and the packet of chocolate biscuits and the packet of custard creams are both chosen?