A router connects to at most K networks. How many routers R are required to connect to N networks? Derive an equation that gives R in terms of N and K.
If N <= K then R = 1 otherwise R = (N -1)/ (K-1) for N > K and K >=2 this is K-1 as one network is linked to two routers. And N- 1 is end router will connect also a network.