It is currently 30 May 2020, 18:56

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# A pottery store owner determines that the revenue for sales

Author Message
TAGS:
Founder
Joined: 18 Apr 2015
Posts: 11192
Followers: 239

Kudos [?]: 2808 [0], given: 10653

A pottery store owner determines that the revenue for sales [#permalink]  14 May 2019, 08:40
Expert's post
00:00

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
A pottery store owner determines that the revenue for sales of a particular item can be modeled by the function $$r(x)= 50 \sqrt{x} −40$$, where x is the number of the items sold. How many of the items must be sold to generate $110 in revenue? (A) 5 (B) 6 (C) 7 (D) 8 (E) 9 [Reveal] Spoiler: OA _________________ Need Practice? 20 Free GRE Quant Tests available for free with 20 Kudos GRE Prep Club Members of the Month: Each member of the month will get three months free access of GRE Prep Club tests. GRE Prep Club Tests Editor Affiliations: Partner at MyGuru LLC. Joined: 13 May 2019 Posts: 151 Location: United States GMAT 1: 770 Q51 V44 GRE 1: Q169 V168 WE: Education (Education) Followers: 6 Kudos [?]: 150 [1] , given: 2 Re: The graph above shows a parabola that is symmetric about the [#permalink] 14 May 2019, 08:53 1 This post received KUDOS Expert's post With all word problems start by skipping to the end to determine the sought value, in this case the number of items sold to generate$110 in revenue. Also, note that the choices are numeric values in numeric order, which indicates that both plugging in the choices and logical estimation are potential tactics. Now, we see the equation that revenue =50√x − 40.

First, recognize that in order to generate the integer value \$110, then formula must result in an integer. Therefore, √x must be an integer, so logically eliminate choices A through D. Were you short on time on the exam, select choice E and move on.

However, you can also plug in choice E 9 to prove that it is correct. 50 x √9 = 150 and 150 - 40 = 110, which matches the conditions of the problem, so of course E is indeed correct.
_________________

Stefan Maisnier

Re: The graph above shows a parabola that is symmetric about the   [#permalink] 14 May 2019, 08:53
Display posts from previous: Sort by