A bag contains $1$ white, $5$ red and $4$ black balls. If three balls are drawn one by one without replacement, then find the probability of drawing a white ball followed by two red balls.

From a bag containing $20$ tickets, numbered from $1$ to $20$, two tickets are drawn at random. Find the probability that

both the tickets have prime numbers on them

From a bag containing $20$ tickets, numbered from $1$ to $20$, two tickets are drawn at random. Find the probability that

on one there is a prime number and on the other there is a multiple of $4$.

An urn contains $4$ red and $7$ blue balls. Two balls are drawn at random with replacement. Find the probability of getting $2$ red balls.

An urn contains $4$ red and $7$ blue balls. Two balls are drawn at random with replacement. Find the probability of getting $2$ blue balls.

An urn contains $4$ red and $7$ blue balls. Two balls are drawn at random with replacement. Find the probability of getting one red and one blue ball.

Three balls are drawn one by one without replacement from an urn containing $3$ white,  $3$ red and $3$ black balls. What is the probability that at least one ball is red?

A box contains $100$ tickets numbered $1$ to $100$. If $5$ tickets are drawn successively with replacement from the box, find the probability that all the tickets bear numbers divisible by $10$.

One bag contains  $3$ white balls, $7$ red balls and $15$ black balls. Another bag contains $10$ white balls, $6$ red balls and $9$ black balls. One ball is taken from each bag. Find the probability that both balls will be of the same colour.