Assume a link with $3$ Mbps is shared among a number of users such that a user transmits continuously at $1$ Mbps$,$ and each user transmits only $30$ percent of the time. Answer the

following questions $(10,11)10.$ If circuit switching is used, how many simultaneous users can use the link?

d$.$ none of the above

d$.1$

$3$ users

c$.0\mathrm{.}027$

b$.2$ users

$11.$ If packet switching is used, suppose there are three users. Find the probability that at any given time, all three users are transmitting simultaneously.

b$.0\mathrm{.}343$

a$.$ Only one user

a $0\mathrm{.}21$