Q15 of 31 Page 7

In how many ways can 5 red, 3 yellow and 4 green discs be arranged in a row if the discs of the same colour are indistinguishable?

Total number of discs= 5 Red + 3 Yellow+ 4 green


n = 12


Since colours are repeating so we use the formula .


Here p1=5 , p2=3, p3= 4


Total ways



= 12× 11× 10× 7× 3


= 27720 ways


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