The chances to fail in Physics are $20\%$ and the chances to fail in Mathematics are $10\%$. What are the chances to fail in at least one subject? ............ $\%$

If $P(A \cup B)=0.8$ and $P(A \cap B)=0.3$, then $P(\bar{A})+P(\bar{B})$ is equal to:

Suppose that a die (with faces marked $1$ to $6$) is loaded in such a manner that for $K = 1, 2, 3, 4, 5, 6$,the probability of the face marked $K$ turning up when the die is tossed is proportional to $K$. The probability of the event that the outcome of a toss of the die will be an even number is equal to

$A$ fair coin and an unbiased die are tossed. Let $A$ be the event 'head appears on the coin' and $B$ be the event '$3$ on the die'. Check whether $A$ and $B$ are independent events or not.

$A$ die is thrown. Find the probability of the following event: $A$ number less than $6$ will appear.

$A$ family with three children is chosen at random. The probability that the oldest and youngest children are of the same gender is