$A$ coin is tossed $3$ times. Find the chance that head and tail show alternately.

One ticket is drawn at random out of $30$ tickets numbered from $1$ to $30.$ Find the probability that the number on the ticket is a multiple of $5$ or $7.$

$A$ single letter is selected at random from the word $PROBABILITY$. The probability that the selected letter is a vowel is

In a class,$30 \%$ of students passed English,$20 \%$ passed French and $10 \%$ passed both. If a student is selected at random,what is the probability that he has passed English or French?

$A$ Chartered Accountant applies for a job in $2$ firms $X$ and $Y$. The probability of his being selected in firm $X$ is $0.7$,and being rejected at $Y$ is $0.5$,and the probability of at least $1$ of his applications being rejected is $0.6$. What is the probability that he will be selected in $1$ of the firms?

If two regular six-sided dice are thrown,the probability that the sum will be a prime number is