$4$ coins are tossed once. Find the probability of getting exactly $3$ tails.

In a certain town,$40\%$ of the people have brown hair,$25\%$ have brown eyes,and $15\%$ have both brown hair and brown eyes. If a person selected at random from the town has brown hair,what is the probability that they also have brown eyes?

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

One ticket is drawn at random out of $30$ tickets numbered from $1$ to $30.$ Find the probability that the number on the ticket is a multiple of $5$ or $7.$

$A$ bag contains $3$ red and $7$ black balls. Two balls are taken out at random,without replacement. If the first ball is red,what is the probability that the second ball is also red?

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 at least one success.