In order to get at least once a head with probability $ \ge 0.9,$ the number of times a coin needs to be tossed is
$3$
$4$
$5$
None of these
In a throw of three dice, the probability that at least one die shows up $1$, is
The probability that a leap year will have $53$ Fridays or $53$ Saturdays is
Out of $60 \%$ female and $40 \%$ male candidates appearing in an exam, $60\%$ candidates qualify it. The number of females qualifying the exam is twice the number of males qualifying it. A candidate is randomly chosen from the qualified candidates. The probability, that the chosen candidate is a female, is.
A card is selected from a pack of $52$ cards. Calculate the probability that the card is black card.
A man and a woman appear in an interview for two vacancies in the same post. The probability of man's selection is $1/4$ and that of the woman's selection is $1/3$. What is the probability that none of them will be selected