Two events are defined such that P(A) =.11 and P(B) = .7 and n(B) = 14

Question

How would I go about calculating P(A') and n(U)?

Answer 1

If P(A) = 0.11, then P(A') = 1 - 0.11 = 0.89. A' is basically "not A", so if the probability of A happening is 0.11, then the probability of it not happening is 1 - 0.11 = 0.89.

If n(B) = 14, and P(B) = 0.7, then n(U) can be calculated by a proportion equation. 0.7 is the same as 7/10, so

7 14

--- = ----

10 n(U)

7n(U) = 140

n(U) = 20