If the lengths of the sides of a triangle are decided by the three throws of a single fair die, then the probability that the triangle is of maximum area given that it is an isosceles triangle, is
$\frac{1}{21}$
$\frac{1}{27}$
$\frac{1}{15}$
$\frac{1}{26}$
A fair coin is tossed repeatedly. If tail appears on first four tosses then the probability of head appearing on fifth toss equals
A coin is tossed twice, what is the probability that atleast one tail occurs ?
If $A$ and $B$ are mutually exclusive events, then the value of $P (A$ or $B$) is
On her vacations Veena visits four cities $(A,\,B ,\, C$ and $D$ ) in a random order. What is the probability that she visits $A$ either first or second?
One card is drawn from a well shuffled deck of $52$ cards. If each outcome is equally likely, calculate the probability that the card will be not a black card.