There are seven intersection with traffic signals between Tristan’s and Isolde’s homes. If x denotes the number of signals at which Tristan must stop because of a red light on a randomly selected trips to Isolde’s place, the probability distribution of x is
X 0 1 2 3 4
P(x) 0.15 0.05 0.10 0.40
The missing entry in the table is
(a)0.30
(b) 0.25
(c) 0.00
(d) 0.15
(e) 0.35
