A historical study was conducted to examine the origin of wars. This resulted in the following probability distribution for X, the number of wars beginning in a year.
f(0)=0.52, f(1)=-0.3, f(2)= 0.10, f(3)=0.10, f(4)=0.03, f(5+)=0.01, and f(x)=0 otherwise
What is the probability that exactly two wars begin in a year given at least one war begins?