Consider 20 DS0 circuits that are multiplexed onto 3 outgoing circuits. The mean

arrival rate at each DS0 circuit is 1 call per hour during the busy hour; calls last, on

average, 5 minutes. Assume Poisson arrivals, exponentially distributed call durations,

and that customers that attempt a call when all circuits are busy are blocked (ignore

call retry).

The probability of blocked calls is . (Use 2 digits to the right of the decimal point.)

(hint: DS0 circuit is essentially traditional wired phone circuit. So, the question

essentially means there are 20 incoming phone lines, 3 outgoing phone lines)