If Pr(a) = .5 and Pr(b) = .3, then the value of Pr(a&b):
A) equals .8.
B) equals .375.
C) equals .15.
D) equals .2.
E) cannot be determined without more information.

Question

Quizplus · Accepted Answer

The probability of both events a and b occurring together (Pr(a&b)) depends on whether events a and b are independent or not, and if they are not independent, on the nature of their dependence. Without this information, it's impossible to accurately calculate Pr(a&b).