In how many ways can 5 flags, in which 3 are red, one is white and once is blue, be arranged on a staff, one below the other, if flags of one colour are not distinguishable?

In how many ways can 4 red,3 yellow and 2 green discs be arranged in a row if the discs of the same colour are indistinguishable?

In how many ways can 4 red,3yellow and 2 green discs be arranged in a row if the discs of the same colour are indistinguishable?

In how many ways can 4 different books, one each in chemistry, physics, biology and mathematics, be arranged on a shelf?

In how many ways can 5 red and 4 white balls be drawn from a bag containing 10 red and 8 white balls

In how many ways 2 blue,3 green and 4 red flags can be arranged vertically to make different signals?

In how many ways can 6 balls of different colours, namely black, white, blue, red, green and yellow be arranged in a row in such a way that the black and white balls ar never together?

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 the 8 marbles are drawn, determine the number of different arrangements if marbles of same colour are indistinguishable.