The probability of obtaining an even number on each die,when a pair of dice is rolled is . . . . . . .

$A$ fair coin with $1$ marked on one face and $6$ on the other and a fair die are both tossed. Find the probability that the sum of numbers that turn up is $3$.

If the roots of each of the equations $2x^2+x-1=0$, $3x^2-10x+3=0$, and $6x^2+11x-2=0$ correspond to probabilities of three events of a random experiment, then those events are

Four persons independently solve a certain problem correctly with probabilities $\frac{1}{2}, \frac{3}{4}, \frac{1}{4}, \frac{1}{8}$. Then the probability that the problem is solved correctly by at least one of them is

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

Let $A$ and $B$ be two events such that the probability that exactly one of them occurs is $\frac{2}{5}$ and the probability that $A$ or $B$ occurs is $\frac{1}{2}$,then the probability of both of them occurring together is