Jones has worked at Firm X twice as many years as Green, and Green has

Question

Jones has worked at Firm X twice as many years as Green, and Green has worked at Firm X four years longer than Smith. How many years has Green worked at Firm X ?

(1) Jones has worked at Firm X 9 years longer than Smith.
(2) Green has worked at Firm X 5 years less than Jones.

DS13602.01
OG2020 NEW QUESTION

DavidTutorexamPAL · Accepted Answer

We'll break our question down into equations, making it easier to understand.
This is a Precise approach.

We know that
jones = 2 * green
green = 4 + smith

This is 2 equations with 3 variables, so we need one more equation to solve
(1) this gives jones = 9 + smith, another (different) equations. Sufficient.
(2) this gives green = jones - 5, also another (different) equation. Sufficient.

(D) is our answer.

Archit3110 · Answer

given info
j=2g
g=s+4
solve for g
#1
j=9+s
9+s=2g
9+g-4=2g
g=5
sufficient
#2
g=j-5
j=g+5
g+5=2g
g= 5
IMO D

BrentGMATPrepNow · Answer

Given : Jones has worked at Firm X twice as many years as Green, and Green has worked at Firm X four years longer than Smith.   
Let  G  = the number of years Green worked at Firm X
So,  G - 4  = the number of years Smith worked at Firm X (since we're indirectly told Smith worked  4 years less than  Green)
And  2G  = the number of years Jones worked at Firm X (since we're told Jones has worked at Firm X  twice  as many years as Green)

Target question :    How many years has Green worked at Firm X?  
In other words,  "What is the value of G?"

Statement 1 : Jones has worked at Firm X 9 years longer than Smith.  
In other words, (Jones' years) = (Smith's years) + 9
Replace values to get:  2G  = ( G - 4 ) + 9
Simplify: 2G = G + 5
Solve:  G = 5 
The answer to the target question is   Green worked at Firm X for 5 years 
Since we can answer the  target question  with certainty, statement 1 is SUFFICIENT

Statement 2 : Green has worked at Firm X 5 years less than Jones.  
In other words, (Green's years) = (Jones' years) - 5
Replace values to get:  G  = ( 2G ) - 5
Solve:  G = 5 
The answer to the target question is   Green worked at Firm X for 5 years 
Since we can answer the  target question  with certainty, statement 2 is SUFFICIENT

Answer: D

Cheers,
Brent

EMPOWERgmatRichC · Answer

Hi All,

We're told that Jones has worked at Firm X TWICE as many years as Green, and Green has worked at Firm X four years LONGER than Smith. We're asked for the number of years that Green has worked at Firm X. This question can be approached in a couple of different ways, but there's a built-in Algebra 'shortcut' that we can take advantage of. From the given information, we can create a couple of equations - and that should get you thinking about "System Math" (re: 2 variables and 2 unique equations, 3 variables and 3 unique equations, etc.).

To start, we'll use the variables J, G and S for Jones, Green and Smith, respectively. We can then create 2 equations: 
J = 2G 
G = S + 4

We're asked to find the value of G. Right now, we have 3 variables, but just 2 equations. If we can get one more UNIQUE equation involving some combination of these three variables, then we'll have a System of equations - and can solve for all 3 variables.

(1) Jones has worked at Firm X 9 years longer than Smith.

With the information in Fact 1, we can create the following equation: 
J = S + 9 
We now have a third unique equation, so we could solve for all 3 variables - including G. The shortcut is that we don't actually have to do that math; having the necessary equations to do it proves that we COULD get the one value of G that exists to answer the question. 
Fact 1 is SUFFICIENT

(2) Green has worked at Firm X 5 years less than Jones.

With the information in Fact 2, we can create the following equation: 
G = J - 5 
Again, we have a third unique equation, so we could solve for all 3 variables - including G. The shortcut is that we don't actually have to do that math; having the necessary equations to do it proves that we COULD get the one value of G that exists to answer the question. 
Fact 2 is SUFFICIENT

Final Answer:  D

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

ScottTargetTestPrep · Answer

We can let the number of years Jones, Green, and Smith worked = J, G, and S respectively.

Since Jones has worked at Firm X twice as many years as Green:

J = 2G

Since Green has worked at Firm X four years longer than Smith:

G = S + 4

We see that we have two unique equations, and three total variables, so if we can create one more unique equation with those variables, we can determine G.

Statement One Alone:

Jones has worked at Firm X 9 years longer than Smith.

We can create the equation:

J = 9 + S

Since we have our 3rd equation, statement one is sufficient to determine G.

Statement Two Alone:

Green has worked at Firm X 5 years less than Jones.

We can create the equation:

G = 5 + J

Since we have our 3rd equation, statement two is sufficient to determine G.

Answer: D

SchruteDwight · Answer

The above solutions are too complicated. The question can be solved with one variable only
S=x
G=4+x
J=8+2x

I) 8+2x=x+9 –> x=1
II) 4+x=3+2x –> x=1

avigutman · Answer

Video solution from Quant Reasoning: Subscribe for more: https://www.youtube.com/QuantReasoning? ... irmation=1 https://www.youtube.com/watch?v=D5_5cFHHL6I

GMATinsight · Answer

Answer: Option D

Video solution by  GMATinsight

https://www.youtube.com/watch?v=wZePXdecZDs

bumpbot · Answer

Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.

Jones has worked at Firm X twice as many years as Green, and Green has

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Data Sufficiency (DS) Questions

Jones has worked at Firm X twice as many years as Green, and Green has

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards