A bag contains _____ red balls and $3$ yellow balls and $2$ green balls. Two balls are drawn at random from the bag and the probability of both balls being red is ______.

$a)$ $4, \frac{1}{3}$

$b)$ $2, \frac{1}{20}$

$c)$ $6, \frac{3}{11}$

$d)$ $5, \frac{2}{9}$

In a college, $\frac{1}{5}th$ of the girls and $\frac{1}{8}\mathrm{th}$ of the boys took part in a social camp. The total number of students in the college took part in the camp is:

There are $6$ defective items in a sample of $20$ items. One item is drawn at random. The probability that it is a non-defective item is:

If $\mathrm{P}\left(\mathrm{A}\right)=\frac{2}{3}$, $\mathrm{P}\left(\overline{ \mathrm{A}} \right)$ is

Six persons $A, B, C, X, Y \& Z$ go for an interview. What is the probability of selection of $A$ and $Y$ in the interview?