$A$ coin is tossed $3$ times. The probability of obtaining at least two heads is

$A$ problem in Mathematics is given to three students $A, B, C$ and their respective probabilities of solving the problem are $\frac{1}{2}, \frac{1}{3},$ and $\frac{1}{4}$. What is the probability that the problem is solved?

Three persons work independently on a problem. If the respective probabilities that they will solve it are $\frac{1}{3}$,$\frac{1}{4}$,and $\frac{1}{5}$,then the probability that none of them can solve it is:

Two dice are rolled. If both dice have six faces numbered $1, 2, 3, 5, 7, 11$,then the probability that the sum of the numbers on the uppermost faces is a prime number is:

$A$ bag contains $6$ white,$5$ black,and $4$ red balls. Find the probability of getting a white or a black ball when one ball is drawn from the bag.

Three coins are tossed once. Find the probability of getting no tails.