A small social network contains four people who are network friends with six other people in the network, one person who is network friends with five other people in the network, and six people who are network friends with four other people in the network. The rest are network friends with three other people in the network. The network contains 49 pairs of network friends. (a)
How many people are network friends with three other people in the network?
(b)
How many people are in the network?