A bag contains $3$ white, $3$ black and $2$ red balls. One by one three balls are drawn without replacing them. The probability that the third ball is red, is
$\frac{1}{2}$
$\frac{1}{3}$
$\frac{2}{3}$
$\frac{1}{4}$
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
If $A$ and $B$ are mutually exclusive events, then the value of $P (A$ or $B$) is
A bag contains $19$ tickets numbered from $1$ to $19$. A ticket is drawn and then another ticket is drawn without replacement. The probability that both the tickets will show even number, is
What is the probability that when one die is thrown, the number appearing on top is even
If $E$ and $F$ are events with $P\,(E) \le P\,(F)$ and $P\,(E \cap F) > 0,$ then