Consider a (n x k) crossbar switch with k < n. Suppose the probability of a line being in use is p. What is the probability that the switch is blocked for the next caller?

Consider a (n x k) crossbar switch with k < n. Suppose the probability of a line being in use is p. What is the probability that the switch is blocked for the next caller?


a. 1-(1-p)^(n-k)  

b. (n!/(k!*(n-k)!))*p^k  

c. (p^k)*(1-p)^(n-k)  

d. Sum(j=1,k)((n!/(j!*(n-j)!))*p^j