Three dice are thrown. The sum of the numbers is $15$. What is the chance of getting $4$ on the first die?

$A$ box contains $15$ black and $20$ white balls. What is the probability that when $2$ balls are selected,one is white?

The word '$UNIVERSITY$' is arranged randomly. Then the probability that both '$I$'s do not come together is:

Study the given information carefully and answer the questions that follow: $A$ basket contains $4$ red,$5$ blue and $3$ green marbles. If $3$ marbles are picked at random,what is the probability that at least $1$ is blue?

The probabilities of winning the race by two athletes $A$ and $B$ are $\frac{1}{5}$ and $\frac{1}{4}$ respectively. The probability of winning by neither of them is:

$2$ dice are thrown. Find the probability of getting an odd number on $1$ die and a multiple of $3$ on the other.