srry to misguide u

 i was in a hurry . made a blunder

 

SORRRRRRRRRRy

 

see yes ur r including many other cases

repeated same black pick ups understood

 

 

simply do this......

total no. of ways of picking - no. of pick ups wid no black balls

 

now dis i am 100% sure........... again sorry for prev. blunder