If three cards are chosen at random from a standard deck of playing cards, how many different ways are there to draw the three cards if at least 2 cards are a jack, queen or king
[spoiler]
OA: 2925
IMO:2860[/spoiler]
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By the way 2860 is the right answer. I looked it up on another website;
https://www.omegamath.net/Data/hwkd2.2.html
https://www.omegamath.net/Data/hwkd2.2.html
It works like this.
We have total of 52 cards in a deck of playing cards which contains 4 jack, 4 king and 4 queen.
From the question we need to pick 3 cards such that atleast two cards are jack , queen or a king.
This can be split into 2 parts. First part where only two cards are jack,queen or king and second part where all three cards are jack, queen or a king.
First part can be solved as below:
Adding jack, queen and king cards we get 12 i.e 4+4+4
i.e 12C2 since condition says atleast 2 cards are jack, queen or king.
Now we have remaining 40 cards from which we need to select 1 so 40c1
So it is 12C2*+40C1=2640...1
Similarly Second part in which we need to select all three cards are jack, queen or king
so 12C3 *40C0=220......2
Both 1 and 2 adds to 2860..
Hope logic is clear. Please correct me if I'm wrong.
Thanks,
Shobha
We have total of 52 cards in a deck of playing cards which contains 4 jack, 4 king and 4 queen.
From the question we need to pick 3 cards such that atleast two cards are jack , queen or a king.
This can be split into 2 parts. First part where only two cards are jack,queen or king and second part where all three cards are jack, queen or a king.
First part can be solved as below:
Adding jack, queen and king cards we get 12 i.e 4+4+4
i.e 12C2 since condition says atleast 2 cards are jack, queen or king.
Now we have remaining 40 cards from which we need to select 1 so 40c1
So it is 12C2*+40C1=2640...1
Similarly Second part in which we need to select all three cards are jack, queen or king
so 12C3 *40C0=220......2
Both 1 and 2 adds to 2860..
Hope logic is clear. Please correct me if I'm wrong.
Thanks,
Shobha