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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Urgent query!Please advise

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
Expert replies
by Mayab » Mon Jun 17, 2013 2:44 pm
1) The Natural Woman, a women's health food store, offers its own blends of trail mix. If the store uses 4 different ingredients, how many bins will it need to hold every possible blend, assuming that each blend must have at least two ingredients? (Also, assume that each bin can hold one and only one blend)

I am trying to solve the first question by using the following method; however it is not giving me the same reply.
Since this is an " at least' question: the total number of arrangements less the undesired outcomes should give us the desired outcome. IN this case, the total number of arrangements should be 4!=4*3*2*1=24 and the undesired outcome is to have 1 ingredient and zero ingredient. Having 1 ingredient is equivalent to 4!/3!=4 and having zero ingredients is equivalent to 4!/4!=1 ==> the total undesired outcomes=4+1=5 less the total arrangements =24, which results in the number of bins=24-5=19 . However the answer that you are giving is 11. Where did I go wrong in my analysis?? Please advise. Thanks!
Join the discussion
Source: — Quantitative Reasoning |

by joshcollins » Mon Jul 01, 2013 5:37 pm
Hi,

First off, this doesn't appear to be a permutation question (you used the word "arrangement") since you're blending things together (and when you blend things together, it doesn't matter what goes into the mix first). You need to use the combination formula to solve this. There aren't 24 ways to do things either, but there are:

1 item: 4 ways
2 items: 4!/(2!)(2!) = 6 ways
3 items: 4!/(3!)(1!) = 4 ways
4 items: 1 way

Since the question asks about blending 2 or more ingredients, there are 11 blends that could exist.

-Josh
Join the discussion

by Mike@Magoosh » Tue Aug 27, 2013 5:08 pm
joshcollins wrote:Hi,

First off, this doesn't appear to be a permutation question (you used the word "arrangement") since you're blending things together (and when you blend things together, it doesn't matter what goes into the mix first). You need to use the combination formula to solve this. There aren't 24 ways to do things either, but there are:

1 item: 4 ways
2 items: 4!/(2!)(2!) = 6 ways
3 items: 4!/(3!)(1!) = 4 ways
4 items: 1 way

Since the question asks about blending 2 or more ingredients, there are 11 blends that could exist.

-Josh
Josh & Mayab,

For some tips on doing this nCr calculations, see this post.
https://magoosh.com/gmat/2012/gmat-math- ... binations/

Mike :-)
Magoosh GMAT Instructor
https://gmat.magoosh.com/
Join the discussion