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

$A$ group of $4$ students is to be formed from among $4$ girls and $6$ boys. What is the probability that the group has less number of boys than the number of girls?

The probability of a sure event is

Study the given information carefully to answer the question that follows. An urn contains $4$ green,$5$ blue,$2$ red,and $3$ yellow marbles. If $2$ marbles are drawn at random,what is the probability that both are red or at least $1$ is red?

The probabilities that a student will receive an $A$, $B$, $C$, or $D$ grade are $0.30$, $0.38$, $0.22$, and $0.01$ respectively. What is the probability that the student will receive at least $B$ grade?

An urn contains $6$ blue,$4$ red,$3$ green,and $2$ yellow marbles. If three marbles are picked at random,what is the probability that $2$ are red and $1$ is green?