Let A, B, and C be events such that A and B are both subsets of C. Also, let P(A) = 0.3, P(B) = 0.4, and P(C) = 0.6. Then, P(A|B) could be what Let A, B, and C be events such that A and B are both subsets of C. Also, let P(A) = 0.3, P(B) = 0.4, and P(C) = 0.6. Then, P(A|B) could be what, there is hint saying that there is not only one answer and I do not get it.
$$P(A\cup B)\geq \max{\{P(A),P(B)\}}=0.4$$
$$P(A\cup B)\leq \min{\{P(C),P(A)+P(B)\}}=0.6$$
$$P(A\cup B)\in[0.4,0.6]$$
$$P(AB)=P(A)+P(B)-P(A\cup B)\in[0.1,0.3]$$
$$P(A|B)=\frac{P(AB)}{P(B)}\in[0.25,0.75]$$
$$0.6\geq P(A\cup B)=0.3+0.4-P(A\cap B).$$

Thus, $$P\left(A|B\right)=\frac{P(A\cap B)}{P(B)}\geq\frac{0.1}{0.4}\geq\frac{1}{4}.$$
Also, use that $P(A\cap B)\leq P(A).$