BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Several friends in a dinner group decide to contribute equally...

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 2539
Joined: Sun Oct 29, 2017 2:04 pmFollowed by: 6 members
by swerve » Tue Jan 14, 2020 11:25 am
Several friends in a dinner group decide to contribute equally to the purchase of a $36 gift. How many people are in the group?

1) The number of people in the group is equal to the size of each person's contribution, in dollars.
2) If three more people joined the group, each person's individual contribution would fall by $2.

The OA is D

Source: Manhattan Prep
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
Legendary Member
Posts: 2214
Joined: Fri Mar 02, 2018 2:22 pmFollowed by: 5 members

Re: Several friends in a dinner group decide to contribute equally...

by deloitte247 » Sat Jan 18, 2020 6:52 pm
Let the total number of friends in the dinner group = x
Let one contribution = y
Total contributions for gift = x * y = $36
Question: How many people are in the group? i.e we want to find the value of x.
From the contribution; xy = 36; x = 36/y
Statement 1: The number of people in the group is equal to the size of each person's contribution in dollar.
i.e x=y and y=x
From the calculation, xy = 36 (substitute y with x because y=x and x=y)
Therefore, x * x = 36 $$x^2=36,\ and\ x=\sqrt{36}=6$$
Based on this, state,emt 1 is SUFFICIENT.

Statement 2: If 3 more people joined the group, each person's individual contribution would fall by $2.
3 people joined the group => x + 3
Individual contribution => y - 2
Total contribution for gift = (x+3)(y-2) = $36
xy - 2x + 3y - 6 = 36
subsitute xy with 36 because xy=36 from the question stem
36 - 2x + 3y - 6 = 36
- 2x + 3y = 6
from xy=36; y=36/x
Therefore,
$$-2x+3\left(\frac{36}{x}\right)=6$$
$$-2x+\frac{108}{x}=6$$
$$-2x^2-6x+108=0$$
Divide through by -2
$$x^2+3x-54=0$$
(x - 6)(x + 9) = 0
x=6 or x=-9
Since contribution cannot be negative, then x=6.
Therefore, statement 2 is SUFFICIENT. Hence, each statement alone is sufficient, the correct answer is option D.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1