A box contains $3$ white and $2$ red balls. A ball is drawn and another ball is drawn without replacing first ball, then the probability of second ball to be red is
$\frac{8}{{25}}$
$\frac{2}{5}$
$\frac{3}{5}$
$\frac{{21}}{{25}}$
The probability of drawing a white ball from a bag containing $3$ black balls and $4$ white balls, is
Three dice are thrown simultaneously. What is the probability of obtaining a total of $17$ or $18$
The probability of hitting a target by three marksmen are $\frac{1}{2},\,\frac{1}{3}$ and $\frac{1}{4}$ respectively. The probability that one and only one of them will hit the target when they fire simultaneously, is
A coin is tossed. If it shows head, we draw a ball from a bag consisting of $3$ blue and $4$ white balls; if it shows tail we throw a die. Describe the sample space of this experiment.
Four coins are tossed. The probability that at least one head turns up, is