General

General

# Nine nickels and a traditional balance are sitting in front

of you. All nickels have...
Nine nickels and a traditional balance are sitting in front of you. All nickels have the same weight except for one counterfeit, which is slightly heavier than the others. What is the lowest maximum number of times you expect to use the balance to guarantee you've found the counterfeit nickel? Please explain the process you would take.
Show More
Show Less
7/22/2010
Chris Miller, Internet Researcher
Category: General
Satisfied Customers: 2,788
Experience: Master's degree in social work, computer knowledge, strong math and science background
Verified

Hello,

It actually can be done in just two weighings.

(1) Divide the coins into three groups (A, B, and C) of three coins each.
Weigh A against B. If neither group is heavier, rename group C "D"; if A or B is heavier, rename that group "D"
Go to the next weighing.
(2) Weigh two coins from group D against each other. If either is heavier, that one is the counterfeit; if they weigh the same, then it is the third coin in group D that is the counterfeit.

Hope this helps!

Chris Miller, Internet Researcher
Category: General
Satisfied Customers: 2,788
Experience: Master's degree in social work, computer knowledge, strong math and science background
Verified
Chris Miller, Internet Researcher
Category: General
Satisfied Customers: 2,788
2,788 Satisfied Customers
Experience: Master's degree in social work, computer knowledge, strong math and science background

Chris Miller is online now

A new question is answered every 9 seconds

• Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
• Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

## What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

## Meet the Experts:

Ellen

Consultant

109 satisfied customers

attorney and legal researcher

P. Simmons

Attorney

140 satisfied customers

45 years old, retired Marine Officer, current attorney

Kim D.

Consultant

34 satisfied customers

Researcher 25 yrs in small and large institutions

SuperiorConsultant

Internet Researcher

21 satisfied customers

BBA, serving as Marketing Executive and interested in tourism,sports, and anything and everything!

Cher

Educator-40+ yrs

1,678 satisfied customers

M.A., B.A., Author, Information & Research Specialist

Michael

Librarian

1,650 satisfied customers

20+ years as information professional

Martin

Engineer

874 satisfied customers

i'm 41 and i never stopped studying and experimenting

< Previous | Next >

Related General Questions
Glenda B. Appraiser
Antique Appraiser
College
8,732 satisfied customers
My best friend just got engaged today, which is awesome.
My best friend just got engaged today, which is awesome. However she wants her wedding in June next year when I will be in Europe, a trip I have had planned since this past April. Should Cancel my tri… read more
TherapistJen
Master\u0027s Degree
951 satisfied customers
Is the surname Rabun......Jewish.? My great grandfather was
My great grandfather was ***** ***** Rabun (mothers side). I had found online that this surname may be Jewish..... … read more
Olivia Kent
Managing Partner
Doctoral Degree
1,679 satisfied customers
What if she wanted to work in a completely different field?
Thank you. What if she wanted to work in a completely different field? Like teaching? Or social work? In that case go to grad school?… read more
Mary Baker
Owner
BA
6 satisfied customers
How do I get mould killer off a new jacket. It has bleached
Hi there! How do I get mould killer off a new jacket. It has bleached a large part of it. Thanks… read more
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
I have A TWO AS I in my surname at iowas you can spell out
I have A TWO AS I in my surname at iowas you can spell out the a two as i at and as is in the at as at … read more
Schuyler
1,944 satisfied customers
How.much would it cost to ship this protein power on the
How.much would it cost to ship this protein power on the link below from NYC to Sao Paulo (Brazil) through USPS and through UPS? This is the zip code in Sao Paulo : 01329-010 https://www.amazon.com/gp… read more
Mary Baker
Owner
BA
6 satisfied customers
Below is some apparel production instruction that we
Below is some apparel production instruction that we created. Please proof read and make correction as needed.• Check if high level of Hydrophilic Nonionic Silicone Softener is used with your own eyes… read more
Mary Baker
Owner
BA
6 satisfied customers
Had been dating guy for a little over a month. Sex was
Had been dating guy for a little over a month. Sex was amazing and it seems lately that's all we did. I know it was quick but we started not using protection. Eleven days ago, I blocked his messages a… read more
Mary Baker
Owner
BA
6 satisfied customers
LIBRARIAN ONLY, how are you? You answered me a question
BRARIAN ONLY Hi Michael, how are you? You answered me a question regarding heated pants and I bought the harley davidson one, but it only charges with motorcycle batteries. Also, it's not as nice as t… read more
Michael
Librarian
Bachelor's Degree
1,650 satisfied customers
WHAT % OF FUNDS COLLECTED GO TO ACTUAL MEDICAL PROCEDURES
WHAT % OF FUNDS COLLECTED GO TO ACTUAL MEDICAL PROCEDURES AND HOW MUCH TO ADMINISTRANT? … read more
Master's Degree
180 satisfied customers
How do i find my brother. W g coupe. Had terminal prostrate
how do i find my brother JA: The Expert will know what to do. Please tell me everything you can so the Expert can help you best. Customer: w g coupe JA: Is there anything else the Expert should be awa… read more
Mary Baker
Owner
BA
6 satisfied customers
A friend has suggested that I explore authentic movement
Hi. A friend has suggested that I explore authentic movement which is a form of dance. Does anyone have any experience with this? Thanks.… read more
Michael
Librarian
Bachelor's Degree
1,650 satisfied customers
I need the recipe for smoke ham that comes with brinkmann
I need the recipe for smoke ham that comes with brinkmann smoker … read more
Mary Baker
Owner
BA
6 satisfied customers
Find me travel plans from Binghampton NY to Charlotte NC.
Please find me travel plans from Binghampton NY to Charlotte NC. Depart on Dec 23 from Binghamton to Charlotte. Return on Dec 26 from Charlotte NC to Binghampton. Please provide links. Looking to do r… read more
Schuyler
1,944 satisfied customers
Where do I go to find bus driver training modules. Acer that
when to buslinesgroup trying to fine the right modules according to the paper I have I just go to http://www.buslinesgroup.com.au/modules.php but I carnt find right one … read more
Schuyler
1,944 satisfied customers
I'm trying to find my child a rectangle trampoline. Can you
I'm trying to find my child a long rectangle trampoline. Can you help me find one? Most I've seen are around \$400.… read more
Michael
Librarian
Bachelor's Degree
1,650 satisfied customers
I would like to order some UPS socks for my son, Averett,
I would like to order some UPS socks for my son, William Averett, who is a UPS driver in Birmingham, Alabama. Can you assist me in getting into the site to order these items. Thanks. … read more
Chris L.
IT/Web Manager