from a pack of 52 playing cards, half of the cards are randomly removed without looking at them. From the remaining cards, 3 cards are drawn randomly. The probability that all are king is
Three cards can be drawn in 52C3 ways...= 22100
now we want at least two kings. there are 4 king in a pack of 52 cards.
at least two means we can have 2 or 3 (4 kings we cant draw as maximum no of cards drawn is three only).
drawing two kings = 4C2= 6 ways
drawing three kings 4C3 = 4 ways
but we have drawn three cards all together
one card can be any card
so when we draw 2 kings from 4 kings we have remaining 48 cards from which one card can be drawn
so total ways = 4C2(drawing two kings) * 48C1 (drawing one card from the remaining cards) = 6* 48= 288 ways
here we have multiplied the combinations bec in prob if our purpose is not solved then we have to multiply ..here we have to draw three cards..2 kings and one any of the cards ...so we have multiplied
now when we draw three kings out of four kings then we dont have to draw any more cards from the remaining cards as in ques we have to draw three cards only
so 4C3 * 48C0= 4 ways
so total favourable ways= 288 + 4 = 292 ways
so required probability is 292/22100 = .013