Three of the six vertices of a regular hexagon are chosen at random. The probability that the triangle formed by these three vertices is equilateral is:

Three unbiased coins are tossed once. What is the probability of getting at most two heads?

$A$ box contains $2$ black,$4$ white,and $3$ red balls. One ball is drawn at random from the box and kept aside. From the remaining balls in the box,another ball is drawn at random and kept aside the first. This process is repeated until all the balls are drawn from the box. The probability that the balls drawn are in the sequence of $2$ black,$4$ white,and $3$ red is

If any four numbers are selected and they are multiplied,then the probability that the last digit of the product will be $1, 3, 5$ or $7$ is

From $21$ tickets numbered $1, 2, 3, \ldots, 21$,one ticket is drawn at random. Find the probability that the ticket drawn has a number divisible by $3$.

The chance of India winning the toss is $3/4$. If it wins the toss,then its chance of victory is $4/5$,otherwise it is only $1/2$. Then the chance of India's victory is