OG 2017 Ratio Question

[mv2019]

The only articles of clothing in a certain closet are shirts, dresses, and jackets. The ratio of the number of shirts to the number of dresses to the number of jackets in the closet is 9:4:5, respectively. If there are more than 7 dresses in the closet, what is the total number of articles of clothing in the closet?

(1) The total number of shirts and jackets in the closet is less than 30.

(2) The total number of shirts and dresses in the closet is 26.

[DavidG@VeritasPrep]

The only articles of clothing in a certain closet are shirts, dresses, and jackets. The ratio of the number of shirts to the number of dresses to the number of jackets in the closet is 9:4:5, respectively. If there are more than 7 dresses in the closet, what is the total number of articles of clothing in the closet?

(1) The total number of shirts and jackets in the closet is less than 30.

(2) The total number of shirts and dresses in the closet is 26.

Number of shirts: 9x
Number of dresses: 4x
Number of jackets: 5x
Total articles of clothing: 18x


If there are more than 7 dresses, and the number of dresses is 4x, we know that x must be at least 2, giving us a minimum of 8 dresses. To the statements!

S1: we know that 9x + 5x < 30, or that 14x < 30. We also know that x cannot be 1, as we'd have fewer than 7 dresses in that scenario. Therefore x must be 2. (If x = 3, then 14x would not be less than 30.) Total articles of clothing = 18*2 = 36. Sufficient.

S2: 9x + 4x = 26. 13x = 26. x = 2. Same information. This is also sufficient. The Answer is D.

[Danny@GMATAcademy]

Here's a video explanation for this question: https://www.youtube.com/watch?v=5iFLsVP2MO0


For more on the method used in the video above, see the videos below:

Intro to the chart method for ratios: https://www.youtube.com/watch?v=WfHm5SF95vU
Using the ratio chart in Data Sufficiency: https://www.youtube.com/watch?v=MA686n6S4z8

[[email protected]]

Hi mv2019,

This DS question can be solved rather easily with a bit of 'brute force' and some simple arithmetic. To start, it's worth noting that you CANNOT have a 'fraction' of a piece of clothing. We're told that the ratio of shirts:dresses:jackets is 9:4:5, so the number of shirts MUST be a multiple of 9, the number of dresses MUST be an equivalent multiple of 4 and the number of jackets MUST be an equivalent multiple of 5. I'm going to put together a quick list of the first few potential possibilities...

There COULD be...
9 shirts/4 dresses/5 jackets
18 shirts/8 dresses/10 jackets
27 shirts/12 dresses/15 jackets
36 shirts/16 dresses/20 jackets
Etc.

We're also told that there are MORE than 7 dresses. We're asked for the total number of articles of clothing.

(1) The total number of shirts and jackets in the closet is less than 30.

With this Fact, we can look at our notes and find whatever options fit this information (AND include MORE than 7 dresses). There's only one...

18 shirts/8 dresses/10 jackets
Fact 1 is SUFFICIENT.

(2) The total number of shirts and dresses in the closet is 26.

With this Fact, we can again look at the available options. There's only one...

18 shirts/8 dresses/10 jackets
Fact 2 is SUFFICIENT.

Final Answer: D

GMAT assassins aren't born, they're made,
Rich

[Matt@VeritasPrep]

S1:

We know that Shirts + Jackets = 9*(some integer) + 5*(some integer) = 14*(some integer)

Since this number < 30, we must have 14 or 28. But if we only have 14, then we'd have 4 dresses (ratio 9 : 4 : 5) ... and we've got more than 4 dresses! So the only possibility is 28, with 8 dresses and a ratio of 18 : 8 : 10. SUFFICIENT

S2:

Similar to the above, we'd have 9*some integer + 4*some integer = 26, so "some integer" = 2, and we're set: we know that the ratio multiplier is 2. SUFFICIENT

[Scott@TargetTestPrep]

The only articles of clothing in a certain closet are shirts, dresses, and jackets. The ratio of the number of shirts to the number of dresses to the number of jackets in the closet is 9:4:5, respectively. If there are more than 7 dresses in the closet, what is the total number of articles of clothing in the closet?

(1) The total number of shirts and jackets in the closet is less than 30.

(2) The total number of shirts and dresses in the closet is 26.

We are given that the ratio of shirts to dresses to jackets is 9 to 4 to 5. Thus:

shirts : dresses : jackets = 9x : 4x : 5x

We also are given that there are more than 7 dresses in the closet and must determine the total number of articles of clothing in the closet, i.e., the value of 9x + 4x + 5x = 18x.

Statement One Alone:

The total number of shirts and jackets in the closet is less than 30.

Using the information in statement one, we can create the following inequality:

9x + 5x < 30

14x < 30

x < 30/14

x < 2 1/7

Thus, x could either be 1 or 2.

If x = 1, then there are 4 dresses. If x = 2, then there are 8 dresses. Since the number of dresses is greater than 7, x must be 2. So there are 9(2) + 4(2) + 5(2) = 18 + 8 + 10 = 36 articles of clothing in the closet. Statement one alone is sufficient to answer the question. We can eliminate answer choices B, C, and E.

Statement Two Alone:

The total number of shirts and dresses in the closet is 26.

Using the information in statement two, we can create the following equation:

9x + 4x = 26

13x = 26

x = 2

Once again, since we have determined the value of x, we have enough information to answer the question. Statement two is also sufficient to answer the question.

Answer: D

[Brent@GMATPrepNow]

The only articles of clothing in a certain closet are shirts, dresses, and jackets. The ratio of the number of shirts to the number of dresses to the number of jackets in the closet is 9:4:5, respectively. If there are more than 7 dresses in the closet, what is the total number of articles of clothing in the closet?

(1) The total number of shirts and jackets in the closet is less than 30.

(2) The total number of shirts and dresses in the closet is 26.

Target question: What is the total number of articles of clothing in the closet?

Given: The ratio of the number of shirts to the number of dresses to the number of jackets in the closet is 9:4:5, respectively.
If shirts : dresses : jackets = 9 : 4 : 5, then there are infinitely many scenarios:
- There are 9 shirts, 4 dresses and 5 jackets
- There are 18 shirts, 8 dresses and 10 jackets
- There are 27 shirts, 12 dresses and 15 jackets
- There are 36 shirts, 16 dresses and 20 jackets
- There are 45 shirts, 20 dresses and 25 jackets
etc...

Also given: There are more than 7 dresses in the closet
This means the first scenario (9 shirts, 4 dresses and 5 jackets) is not possible. This leaves us with the following cases:
case i: 18 shirts, 8 dresses and 10 jackets
case ii 27 shirts, 12 dresses and 15 jackets
case iii 36 shirts, 16 dresses and 20 jackets
case iv 45 shirts, 20 dresses and 25 jackets
.
.
.
etc


Statement 1: The total number of shirts and jackets in the closet is less than 30
When we check the possible cases, we see that only case i meets this condition.
This means there MUST be 18 shirts, 8 dresses and 10 jackets
So, the answer to the target question is the total number of articles of clothing = 18 + 8 + 10 = 36
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: The total number of shirts and dresses in the closet is 26
Only case i meets this condition.
So, the answer to the target question is the total number of articles of clothing = 18 + 8 + 10 = 36
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: D

Cheers,
Brent