• 7 CATs FREE!
If you earn 100 Forum Points

Engage in the Beat The GMAT forums to earn
100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote ## A certain family has 3 sons: Richard is 6 years older than D ##### This topic has 2 expert replies and 1 member reply ### Top Member ## A certain family has 3 sons: Richard is 6 years older than D ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult A certain family has 3 sons: Richard is 6 years older than David, and David is 8 years older than Scott. If in 8 years, Richard will be twice as old as Scott, then how old was David 4 years ago? (A) 8 (B) 10 (C) 12 (D) 14 (E) 16 OA B Source: Princeton Review ### Top Member Junior | Next Rank: 30 Posts Joined 03 Oct 2018 Posted: 10 messages Let R, D and S be the present ages of Richard, David and Scott respectively. Therefore we can formulate the given equations from the data given R=D+8 D=S+8 Also after 8 years, Richard will be twice as old as Scott, giving us the equation R+8=(S+8) Solving these 3 equations , we get D=14 Thus, the age of David 4 years ago would be 10. ### GMAT/MBA Expert GMAT Instructor Joined 09 Oct 2010 Posted: 729 messages Followed by: 26 members Upvotes: 59 BTGmoderatorDC wrote: A certain family has 3 sons: Richard is 6 years older than David, and David is 8 years older than Scott. If in 8 years, Richard will be twice as old as Scott, then how old was David 4 years ago? (A) 8 (B) 10 (C) 12 (D) 14 (E) 16 Source: Princeton Review $$? = D - 4$$ $$R = D + 6\,\,\,\,\mathop \Rightarrow \limits^{ + \,8} \,\,\,\,\,R + 8 = D + 14\,\,\,\left( 1 \right)$$ $$D = S + 8\,\,\,\left( 2 \right)$$ $$R + 8 = 2\left( {S + 8} \right)\,\,\,\,\mathop \Rightarrow \limits^{\left( 1 \right),\left( 2 \right)} \,\,\,D + 14 = 2D\,\,\,\, \Rightarrow \,\,\,\,14 = D$$ $$? = 10$$ This solution follows the notations and rationale taught in the GMATH method. Regards, Fabio. _________________ Fabio Skilnik :: https://GMATH.net (Math for the GMAT) Testimonials :: https://GMATH.net/testimonials.html Course release PROMO : finish our test drive till 31/Oct with (at least) 60 correct answers out of 92 (12-questions Mock included) to gain a 60% discount! ### GMAT/MBA Expert GMAT Instructor Joined 25 Apr 2015 Posted: 1651 messages Followed by: 14 members Upvotes: 43 BTGmoderatorDC wrote: A certain family has 3 sons: Richard is 6 years older than David, and David is 8 years older than Scott. If in 8 years, Richard will be twice as old as Scott, then how old was David 4 years ago? (A) 8 (B) 10 (C) 12 (D) 14 (E) 16 We can create the equations: R = D + 6 and D = S + 8 So we have R = (S + 8) + 6 or R = S + 14. We are also given that in 8 years, Richard will be twice as old as Scott. We express Richardâ€™s age in 8 years as (R + 8) and Scottâ€™s age in 8 years as (S + 8), so we have: R + 8 = 2(S + 8) S + 14 + 8 = 2S + 16 6 = S Therefore, Scott is currently 6 years old and David is 6 + 8 = 14 years old. So 4 years ago, David was 10 years old. Answer: B _________________ Scott Woodbury-Stewart Founder and CEO • 1 Hour Free BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

Available with Beat the GMAT members only code

• 5-Day Free Trial
5-day free, full-access trial TTP Quant

Available with Beat the GMAT members only code

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to \$200

Available with Beat the GMAT members only code

• 5 Day FREE Trial
Study Smarter, Not Harder

Available with Beat the GMAT members only code

• Get 300+ Practice Questions

Available with Beat the GMAT members only code

### Top First Responders*

1 fskilnik@GMATH 74 first replies
2 Jay@ManhattanReview 49 first replies
3 Brent@GMATPrepNow 47 first replies
4 GMATGuruNY 43 first replies
5 Rich.C@EMPOWERgma... 36 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

### Most Active Experts

1 fskilnik@GMATH

GMATH Teacher

195 posts
2 Scott@TargetTestPrep

Target Test Prep

183 posts
3 Brent@GMATPrepNow

GMAT Prep Now Teacher

123 posts
4 Max@Math Revolution

Math Revolution

89 posts
5 GMATGuruNY

The Princeton Review Teacher

87 posts
See More Top Beat The GMAT Experts