• NEW! FREE Beat The GMAT Quizzes
Hundreds of Questions Highly Detailed Reporting Expert Explanations
• 7 CATs FREE!
If you earn 100 Forum Points

Engage in the Beat The GMAT forums to earn

(2) The cost of a square slab that is 3 meters long and 0.1 meter thick is $200 more than the cost of a square slab that is 2 meters long and 0.1 meter thick. OA D Source: GMAT Prep ### GMAT/MBA Expert GMAT Instructor Joined 22 Aug 2016 Posted: 1984 messages Followed by: 30 members Upvotes: 470 Top Reply BTGmoderatorDC wrote: The cost of a square slab is proportional to its thickness and also proportional to the square of its length. What is the cost of a square slab that is 3 meters long and 0.1 meter thick? (1) The cost of a square slab that is 2 meters long and 0.2 meter thick is$160 more than the cost of a square slab that is 2 meters long and 0.1 meter thick.

(2) The cost of a square slab that is 3 meters long and 0.1 meter thick is $200 more than the cost of a square slab that is 2 meters long and 0.1 meter thick. OA D Source: GMAT Prep Say the cost of the slab is C, thickness is T and length is L. It is given C is proportional to T and square of L. Say a constant is K. Thus, C = KTL^2 We are given that T = 0.1 meter, and L = 3 meters Thus, C = K*0.1*3^2 C = 0.9K If we get the value of K, we get the answer. Question rephrased: What's the value of K? Let's take each statement one by one. (1) The cost of a square slab that is 2 meters long and 0.2 meter thick is$160 more than the cost of a square slab that is 2 meters long and 0.1 meter thick.

Slab #1: Values given for L1, and T1. Value of C1 not given.
Slab #2: Values given for L2, and T2. Value of C2 not given.

Say C' = Difference of C1 and C2

C' = K*T1*(L1)^2 - K*T2*(L2)^2
C' = K[T1*(L1)^2 - T2*(L2)^2]

We know that values of C', L1, T1, T2 and L2; thus, the value of K can be calculated. Sufficient.

(2) The cost of a square slab that is 3 meters long and 0.1 meter thick is $200 more than the cost of a square slab that is 2 meters long and 0.1 meter thick. It's the same as Statement 1. Sufficient. The correct answer: D Hope this helps! -Jay _________________ Manhattan Review Locations: Manhattan Review Jayanagar | GMAT Prep Tarnaka | GRE Prep Madhapur | Kukatpally GRE Coaching | and many more... Schedule your free consultation with an experienced GMAT Prep Advisor! Click here. ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 15362 messages Followed by: 1866 members Upvotes: 13060 GMAT Score: 790 Top Reply BTGmoderatorDC wrote: The cost of a square slab is proportional to its thickness and also proportional to the square of its length. What is the cost of a square slab that is 3 meters long and 0.1 meter thick? (1) The cost of a square slab that is 2 meters long and 0.2 meter thick is$160 more than the cost of a square slab that is 2 meters long and 0.1 meter thick.

(2) The cost of a square slab that is 3 meters long and 0.1 meter thick is $200 more than the cost of a square slab that is 2 meters long and 0.1 meter thick. x is directly proportional to y implies the following: x/y = k. x = ky. In each case, k is a CONSTANT. The cost of a square slab is proportional to its thickness and also proportional to the square of its length. Thus: c = k * T * LÂ². What is the cost of a square slab that is 3 meters long and 0.1 meter thick? Since c = k * T * LÂ², we get: c = k * 0.1 * 3Â² c = 0.9k. To determine the value of c, we need to know the value of k. Question rephrased: What is the value of k? Statement 1: The cost of a square slab that is 2 meters long and 0.2 meter thick is$160 more than the cost of a square slab that is 2 meters long and 0.1 meters thick.
Cost of a square slab that is 2 meters long and 0.2 meter thick = k * 0.2 * 2Â² = .8k.
Cost of a square slab that is 2 meters long and 0.1 meter thick = k * 0.1 * 2Â² = .4k.
Since the difference in cost is $160, we get: 0.8k - 160 = 0.4 0.4k = 160 k = 160/0.4 = 1600/4 = 400. SUFFICIENT. Statement 2: The cost of a square slab that is 3 meters long and 0.1 meter thick is$200 more than the cost of a square slab that is 2 meters long and 0.1 meter thick.
Cost of a square slab that is 3 meters long and 0.1 meter thick = k * 0.1 * 3Â² = .9k.
Cost of a square slab that is 2 meters long and 0.1 meter thick = k * 0.1 * 2Â² = .4k.
Since the difference in cost is $200, we get: 0.9k - 200 = 0.4k 0.5k = 200 k = 200/0.5 = 2000/5 = 400. SUFFICIENT. The correct answer is D. _________________ Mitch Hunt Private Tutor for the GMAT and GRE GMATGuruNY@gmail.com If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon. Available for tutoring in NYC and long-distance. For more information, please email me at GMATGuruNY@gmail.com. Student Review #1 Student Review #2 Student Review #3 Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now. • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE 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

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• 5 Day FREE Trial
Study Smarter, Not Harder

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

• FREE GMAT Exam
Know how you'd score today for \$0

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

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

• 1 Hour Free
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

### Top First Responders*

1 Brent@GMATPrepNow 41 first replies
2 Ian Stewart 37 first replies
3 Jay@ManhattanReview 32 first replies
4 GMATGuruNY 26 first replies
5 Scott@TargetTestPrep 14 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

### Most Active Experts

1 Scott@TargetTestPrep

Target Test Prep

199 posts
2 Max@Math Revolution

Math Revolution

92 posts
3 Brent@GMATPrepNow

GMAT Prep Now Teacher

74 posts
4 GMATGuruNY

The Princeton Review Teacher

45 posts
5 Ian Stewart

GMATiX Teacher

43 posts
See More Top Beat The GMAT Experts