There are 3 white, 4 red, and 1 blue marbles in a bag. They are drawn one by one and arranged in a row. Assuming that all 8 marbles are drawn, determine the number of different arrangements if marbles of same colour are indistinguishable.

Q. There are 3 red and 4 blue marbles in a bag. At random, one marble is drawn. The probability that the marble drawn is blue:

Q. A bag contains 8 marbles of which 3 are blue and 5 are red. One marble is drawn at random, its colour is noted and the marble is replaced in the bag. A marble is again drawn from the bag and its colour is noted. Find the probability that the marble will be
(i) blue followed by red.
(ii) blue and red in any order.
(iii) of the same colour.

Q. An urn contains marbles of four colours : red, white, blue and green. When four marbles are drawn without
replacement, the following events are equally likely :
(1) the selection of four red marbles;
(2) the selection of one white and three red marbles;
(3) the selection of one white, one blue and two red marbles;
(4) the selection of one marble of each colour.
The smallest total number of marbles satisfying the given condition is

Q. A bag contains 5 red marbles and 3 black marbles. Three marbles are drawn one by one with replacement. What is the probability that all the 3 drawn are black if the first marbel is red?

Q. An urn contains marbles of four colours: red, white, blue and green. When four marbles are drawn without replacement, the following events are equally likely:
$\left(1\right)$ the selection of four red marbles;
$\left(2\right)$ the selection of one white and three red marbles;
$\left(3\right)$ the selection of one white, one blue and two red marbles;
$\left(4\right)$ the selection of one marble of each colour.
The smallest total number of marbles satisfying the given condition is.