In each of the following experiments specify appropriate sample space A person is noting down the number of accidents along a busy highway during a year.
The number of accidents along a busy highway during the year of observation can be either $0$ (for no accident) or $1$ or $2,$ or some other positive integer. Thus, a sample space associated with this experiment is $S =\{0,1,2, \ldots\}$
An integer is chosen at random and squared. The probability that the last digit of the square is $1$ or $5$ is
If $P(A) = 0.65,\,\,P(B) = 0.15,$ then $P(\bar A) + P(\bar B) = $
A box contains $2$ black, $4$ white and $3$ red balls. One ball is drawn at random from the box and kept aside. From the remaining balls in the box, another ball is drawn at random and kept aside the first. This process is repeated till all the balls are drawn from the box. The probability that the balls drawn are in the sequence of $2$ black, $4$ white and $3$ red is
In a class of $60$ students, $40$ opted for $NCC,\,30$ opted for $NSS$ and $20$ opted for both $NCC$ and $NSS.$ If one of these students is selected at random, then the probability that the student selected has opted neither for $NCC$ nor for $NSS$ is
One card is drawn from each of two ordinary packs of $52$ cards. The probability that at least one of them is an ace of heart, is