Given: P(A) = 0.4, P(A or B) = 0.6 and P(B) = 0.5
We know that, P(A or B) = P(A) + P(B) – P(A and B)
By substituting values in the above formula, we get
0.6 = 0.4 + 0.5 – P(A and B)
0.6 = 0.9 – P(A and B)
P(A and B) = 0.9 – 0.6
P(A and B) = 0.3
P(A and B) = 0.3