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Buy "All-In-One Standard ($149)", get free Daily quiz (2 mon). Coupon code : SPECIAL # In a certain store, the ratio of part-time workers to full-time worker  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics Author Message TAGS: ### Hide Tags Senior Manager Joined: 02 Jan 2017 Posts: 307 Location: Canada In a certain store, the ratio of part-time workers to full-time worker [#permalink] ### Show Tags 14 Mar 2017, 02:27 3 00:00 Difficulty: 15% (low) Question Stats: 81% (01:52) correct 19% (02:08) wrong based on 54 sessions ### HideShow timer Statistics In a certain store, the ratio of part-time workers to full-time workers is 2 to 5. If 4 part-time workers were hired, then the ratio would be 3 to 5. How many workers does the store have? (A) 11 (B) 12 (C) 21 (D) 28 (E) 35 Intern Joined: 09 Jan 2017 Posts: 22 Location: Germany Concentration: International Business, General Management GPA: 3.7 Re: In a certain store, the ratio of part-time workers to full-time worker [#permalink] ### Show Tags 14 Mar 2017, 07:50 My Approach 2x+5x=7x $$\frac{2}{5}$$ +4 part time => $$\frac{3}{5}$$ 1x=4 (2*4) + (5*4) = 28 _________________ Kudos for correct answers or good questions! EMPOWERgmat Instructor Status: GMAT Assassin/Co-Founder Affiliations: EMPOWERgmat Joined: 19 Dec 2014 Posts: 13546 Location: United States (CA) GMAT 1: 800 Q51 V49 GRE 1: Q170 V170 Re: In a certain store, the ratio of part-time workers to full-time worker [#permalink] ### Show Tags 28 Nov 2017, 12:36 Hi All, We're told that the ratio of part-time workers to full-time workers is 2 to 5. This means that: 1) The number part-time workers MUST be a multiple of 2 2) The number of full-time workers MUST be a multiple of 5 3) The total number of workers must be a multiple of 7 We're also told that IF 4 part-time workers were hired, then the ratio of part-time workers to full-time workers would be 3 to 5. We're asked for the TOTAL number of workers there are NOW (meaning before 4 part-time workers are hired). This question can be solved in a number of different ways. Since the total number of workers is a multiple of 7 - and the answers are numbers - we can TEST THE ANSWERS. To start, we can eliminate Answers A and B (since they're NOT multiples of 7). Let's TEST Answer D: 28 total workers IF.... there are 28 total workers 8 are part-time and 20 are full-time Adding 4 more part-time workers would give us.... 12 part-time and 20 full-time 12:20 = 3:5 This is an exact match for what we were told, so this MUST be the answer! Final Answer: GMAT assassins aren't born, they're made, Rich _________________ 760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com # Rich Cohen Co-Founder & GMAT Assassin Special Offer: Save$75 + GMAT Club Tests Free
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In a certain store, the ratio of part-time workers to full-time worker  [#permalink]

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28 Nov 2017, 13:05
vikasp99 wrote:
In a certain store, the ratio of part-time workers to full-time workers is 2 to 5. If 4 part-time workers were hired, then the ratio would be 3 to 5. How many workers does the store have?

(A) 11

(B) 12

(C) 21

(D) 28

(E) 35

Another approach: set up the original ratio with x, add the number given, set it equal to the new ratio, and multiplier x gives you the original actual numbers.

The ratio of part-time workers to full-time workers is 2 to 5

$$\frac{Part-time}{Full-time}=\frac{2x}{5x}$$

If 4 part-time workers were hired, then the ratio would be 3 to 5:

$$\frac{2x + 4}{5x}=\frac{3}{5}$$

$$5(2x + 4) = 3(5x)$$
$$10x + 20 = 15x$$
$$20 = 5x$$
$$x = 4$$

x is the multiplier for the original ratio

How many workers (TOTAL)?
Part-time = 2x = (2)(4) = 8
Full-time = 5x = (5)(4)= 20

20 + 8 = 28

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Re: In a certain store, the ratio of part-time workers to full-time worker  [#permalink]

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06 Feb 2019, 18:09
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: In a certain store, the ratio of part-time workers to full-time worker   [#permalink] 06 Feb 2019, 18:09
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