The total number of ways of selecting 10 balls out of unlimited number of identical white , red and blue balls . Please explain the approach required to solve these types of questions .

Here,The word unlimited is just for confusion....there are 10 red balls,10 white balls,10 blue balls out of which we need to select 10 in all possible ways so that W+R+B less than or equal to 10,so that w+r+b+t=10,required ways 10+4-1 c 4-1 = 286.

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