BTGmoderatorLU wrote: ↑

Tue Jul 21, 2020 5:44 am

Source: Official Guide

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.

The OA is D

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