In a box there are 4 blue, 4 red, 4 white and 4 black balls. Four balls are picked up randomly, what is the probability of the following event to occur? All the four balls are of the same colour.

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:

If $n\left(A\right)=2, P\left(A\right)=\frac{1}{5}$, then $n\left(S\right)=$?

Two dice are rolled simultaneously. Find the probability that the sum of the numbers on the faces is neither divisible by $3$ nor by $4$.

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:

A number is selected at random from integers $1$ to $100.$ Find the probability that it is not a perfect cube.

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?