Two dice are thrown simultaneously. What is the probability of getting two numbers whose product is even?

$A$ Chartered Accountant applies for a job in $2$ firms $X$ and $Y$. The probability of his being selected in firm $X$ is $0.7$,and being rejected at $Y$ is $0.5$,and the probability of at least $1$ of his applications being rejected is $0.6$. What is the probability that he will be selected in $1$ of the firms?

$A$ box contains $5$ red,$4$ green and $3$ black balls. $3$ balls are drawn at random. What is the probability that they are not of the same colour?

In an entrance test,there are multiple-choice questions. There are four possible answers to each question,of which one is correct. The probability that a student knows the answer to a question is $90\%$. If he gets the correct answer to a question,then the probability that he was guessing is:

In a lottery,there were $90$ tickets numbered $1$ to $90$. Five tickets were drawn at random. What is the probability that two of the tickets drawn are numbered $15$ and $89$?

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.