$3$ coins are tossed. Find the probability of getting at most $2$ heads.

$A$ locker can be opened by dialing a fixed three-digit code (between $000$ and $999$). $A$ stranger who does not know the code tries to open the locker by dialing three digits at random. The probability that the stranger succeeds at the $k^{th}$ trial is

What is the chance that a leap year,selected at random,will contain $53$ Sundays (in $/7$)?

In a box,there are $8$ red,$7$ blue,and $6$ green balls. One ball is picked up at random. What is the probability that it is neither red nor green?

If any four numbers are selected and they are multiplied,then the probability that the last digit of the product will be $1, 3, 5$ or $7$ is

$A$ bag $x$ contains $3$ white balls and $2$ black balls and another bag $y$ contains $2$ white balls and $4$ black balls. $A$ bag and a ball out of it are picked at random. The probability that the ball is white,is