Suppose that the probability that the price of a commodity goes up today is 0.6 that the probability that it goes up tomorrow is 0.7, and that the probability it goes up both today and tomorrow is 0.5. Find the probability that it goes down or remains the same both today and tomorrow.

Let A =the price goes up today and B=price goes up tomorrow.

we have P(A)=0.6, P(B)=0.7, P(AandB)=0.5

Do they want 1-P(AandB)=0.5?

Thanks