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A Car comes with 7 different possible exterior colors and 6

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A Car comes with 7 different possible exterior colors and 6  [#permalink]

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10 Feb 2011, 11:49
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Difficulty:

15% (low)

Question Stats:

69% (00:38) correct 31% (00:57) wrong based on 152 sessions

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A Car comes with 7 different possible exterior colors and 6 different interior colors. How many different color combinations are there?

$$A. 26$$

$$B. 42$$

$$C. \frac{7!6!}{2!}$$

$$D. 7!6!$$

$$E. \frac{13!}{2!}$$

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10 Feb 2011, 11:56
gmatpapa wrote:
A Car comes with 7 different possible exterior colors and 6 different interior colors. How many different color combinations are there?

$$A. 26$$

$$B. 42$$

$$C. \frac{7!6!}{2!}$$

$$D. 7!6!$$

$$E. \frac{13!}{2!}$$

Why not

For each exterior color out of 7 there are 6 different interior colors possible, so there are total of 7*6=42 color combinations. This is basically the same as Principle of Multiplication: if one event can occur in $$m$$ ways and a second can occur independently of the first in $$n$$ ways, then the two events can occur in $$mn$$ ways.

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10 Feb 2011, 12:36
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$$C^7_1*C^6_1$$
$$7*6=42$$

Ans: "B"
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10 Feb 2011, 15:53
42
This one was suspiciously easy - I spent one minute only thinking about the trap - little bit paranoid.
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Re: A Car comes with 7 different possible exterior colors and 6  [#permalink]

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21 Oct 2014, 14:27
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craky wrote:
42
This one was suspiciously easy - I spent one minute only thinking about the trap - little bit paranoid.

I think that is a common problem. I know I've actually spent too long on a problem because I didn't trust in myself that I could have gotten a problem so easily. One way to get around this is to practice a lot so that you gain more confidence in your abilities and realize that the test will give you very easy questions sometimes.
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Re: Veritas Prep Statistics and Combinatorics Homework Question#74  [#permalink]

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24 May 2015, 22:39
1
sandeepmanocha wrote:
A car is available in seven different exterior colors and six different interior colors. how many unique color combinations are possible?

(A) 26
(B) 42
(C) 7!6!/2!
(D) 7!6!
(E) 13!/2!

OA : (C)

Why the OA is correct, what am I missing? My answer choice is (D)

There are 7 different ways to choose an exterior color and 6 different ways to choose an interior color.
So the number of combinations is 7 * 6 = 42.

(Imagine A B C D E F G are the choices for exterior colors and H I J K L M are the choices for interior colors.
If you choose A as the exterior color you can choose any of H I J K L M as interior color. So 6 combinations when you choose A as exterior.
Similarly
If you choose B as the exterior color you can choose any of H I J K L M as interior color. So 6 combinations when you choose B as exterior.
So you can see that for each exterior color there is an option of 6 interior colors. So total possible combinations = 7*6 = 42 )

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Re: A Car comes with 7 different possible exterior colors and 6  [#permalink]

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01 Dec 2017, 08:00
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

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Re: A Car comes with 7 different possible exterior colors and 6   [#permalink] 01 Dec 2017, 08:00
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