Question

In how many ways, 5 balls can be selected
from infinite number of red and black balls,
such that there is at least one ball of both the
colors?
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Answer 1

Answer:

there is infinite balls so we take..

x black balls and y white balls

find :

at least one ball of bath coulour it means not only 5 black and not only 5 white ball is granted..

so total number of ways is = x+y*C5

there is all 5 balls is black = xc5

there is all 5 balls is white = Yc5

so total needed possiblity = (x+y)C5 - xc5 - Yc5

plese like this sure ans..