7. A user's behaviour in interacting with a database system is as follows (we assume that the user is always connected). There are three actions: query, modify/delete, add. A query action is followed by another query action with probability 0.8, by a modify/delete action with probability 0.18 and by an add operation with probability 0.02. A modify/delete action is followed by a modify/delete action with probability 0.05, otherwise it is followed by a query action. Finally, an add action is always followed by a query action. (a) If the first action is a query, what is the probability that the third action is not a query? (b) In steady-state, what is the probability that one sees two query actions in a row