P (A∩B) = 1150, P (A|B) = 1120, P (B) = ?

Conditional probability can be described using the following rule:

P (A | B) = P (A ∩ B) / P (B)

Now for the givens we have:

P (A∩B) = 1150 and

P (A|B) = 1120

Substituting with these givens in the above mentioned equations, we can get P (B) as follows:

1120 = 1150 / P (B)

P (B) = 1150 / 1120 = 1.02678