Three of the six vertices of a regular hexagon are chosen at random. The probability that the triangle formed by these three vertices is equilateral is:

The probability that a man will be alive $25$ years hence is $0.3$ and the probability that his wife will be alive $25$ years hence is $0.4$. Find the probability that $25$ years hence, at least $1$ of them will be alive.

An integer is chosen at random from the first $200$ natural numbers. What is the probability that the integer chosen is divisible by $6$ or $8$?

An urn contains $25$ balls numbered $1$ to $25$. Suppose an odd number is considered a 'success'. If $2$ balls are drawn from the urn with replacement,find the probability of getting at most $2$ successes.

An urn contains $25$ balls numbered $1$ to $25$. Suppose an odd number is considered a 'success'. $2$ balls are drawn from the urn with replacement. Find the probability of getting exactly $2$ successes.

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