Three coins are tossed once. Find the probability of getting no tails.

Three athletes $A, B$ and $C$ participate in a race competition. The probability of winning for $A$ and $B$ is twice the probability of winning for $C$. Then the probability that the race is won by $A$ or $B$ is:

If a number is chosen at random from the set $\{1, 2, 3, \ldots, 100\}$,then the probability that the chosen number is a perfect cube is

Events $A, B$ and $C$ are mutually exclusive events such that $P(A)=\frac{3x+1}{3}$,$P(B)=\frac{1-x}{4}$ and $P(C)=\frac{1-2x}{2}$. The set of possible values of $x$ is in the interval

If $A$ and $B$ are two events,what is the probability that exactly one of them occurs?

The probability that a student will pass the final examination in both English and Hindi is $0.5$ and the probability of passing neither is $0.1$. If the probability of passing the English examination is $0.75$,what is the probability of passing the Hindi examination?