Each car at a certain dealership is either blue or white. What is the

Question

Each car at a certain dealership is either blue or white. What is the average (arithmetic mean) sticker price of all the cars at the dealership?

(1) Of all the cars at the dealership, 1/3 are blue and have an average sticker price of $21,000.
(2) Of all the cars at the dealership, 2/3 are white and have an average sticker price of $24,000.

ID: 700291
DS96720.02

anilesh10 · Answer

st1-not sufficient as price of white cars not given
st2-not sufficient as price of blue cars not given
combined sufficient

itspCv2 · Answer

STRAIGHT to POINT:

1) the average of white not given
2)the average of blue not given
 
  Now combined: (21k*1+24k*2)/3= average.
Therefore C

Naman1313 · Answer

OA - C

St.1 is insufficient - Blue are 1/3 and average of blue is 21000. Hence, blue is one out of three, but we do not know the ratio of white.

St.2 is insufficient - White are 2/3 and average of white is 24000. Hence, white is two out of three, but we do not know the ratio of blue.

St.1 and 2 combined - blue is 1 and white are two. So, average of 3 is 21000+24000+24000 = 69000/3 = 23000, Hence sufficient.

vrinda6 · Answer

But we still dont know what the total number of cars was. Shouldnt we have taken (1/3)*x and (2/3)*x

Bunuel · Answer

No. We do not need the total number of cars, because the fractions 1/3 and 2/3 already give the weights of the two groups. Using x would give the same result anyway:

Total value = x/3*21000 + 2x/3*24000
Average = (x/3*21000 + 2x/3*24000)/x = 23000

So x cancels out.

IshmaelJN · Answer

What we know:
- Cars are blue (B) or white (W)
- Make X the price of B and Y the price of white
- We are looking to solve for x*B + y*W

1) 1/3=B, thus 2/3=W
1/3*$21,000=$7,000 --> B

$21k + 2/3 * Y=
Insufficient as we still don't know Y

2) 2/3=W, thus 1/3=B
2/3*$24,000=$16,000
1/3*X+$16k=

Insufficient as we still don't know X

Combined:

We know we can solve so we can stop here. See below for completeness:

Blue = $7k
White = $16k
Total = $23k

Each car at a certain dealership is either blue or white. What is the

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GMAT Data Sufficiency (DS) Questions

Each car at a certain dealership is either blue or white. What is the

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