Question 729071
Let x = P(B)


P(A) = 3*P(B) ... This is given when you are told that "Event A is 3 times more likely that Event B"


There are only two outcomes A and B. So their probabilities must add to 1


P(A) + P(B) = 1


3*P(B) + P(B) = 1


3*x + x = 1


4x = 1


x = 1/4


P(B) = 1/4 = 0.25


P(A) = 3*P(B)


P(A) = 3*(1/4)


P(A) = 3/4 = 0.75


So the probability of event A is <font color="red">0.75</font>