GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 18 Oct 2019, 06:43

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Mario's Pizza has two choices of crust: deep dish and thin

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
Joined: 11 Jan 2011
Posts: 57
GMAT 1: 680 Q44 V39
GMAT 2: 710 Q48 V40
GMAT ToolKit User
Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 01 Nov 2013, 18:34
2
3
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

91% (00:47) correct 9% (00:09) wrong based on 36 sessions

HideShow timer Statistics

Mario's Pizza has two choices of crust: deep dish and thin-and-crispy. The restaurant also has a choice of 5 toppings: tomatoes, sausage, peppers, onions, and pepperoni. Finally, Mario's offers very pizza in extra-cheese as well as regular. If Linda's volleyball team decides to order a pizza with four toppings, how many different choices do the teammates have at Mario's Pizza?


My approach (with spoiler):

Total number of choices = 2 crust x 5 toppings x 2 cheese = 20
Vball team: 2 crust x 4 toppings x 2 cheese = 16 choices

I understand this approach is incorrect because instead of first saying choose 4 out of 5 toppings, it essentially eliminates a topping.

However, why would the correct approach, 2 crust x 5c4 toppings x 2 cheese, be the same as the "total" possibilities, 20? Is it just a coincidence that the numbers worked out this way in this problem?


OA = 20
Economist GMAT Tutor Instructor
User avatar
Joined: 01 Oct 2013
Posts: 68
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 01 Nov 2013, 22:15
1
Yes, it is a coincidence that you arrived at the correct answer on this problem. It's unfortunate when that happens, because it's often hard to figure out why the approach is wrong.

Basically, your middle term (5 toppings) is appropriate for selecting 1 topping at a time out of 5 options.

Coincidentally, this parallels the correct approach of selecting 4 toppings at a time out of 5 options. With the latter, you effectively leave out 1 topping for each option, which has the effect of also giving you 5 different combinations.

But notice, having 5 different groupings of 4 toppings each (5c4) is very different from choosing 1 of 5 toppings at a time (5c1). They just happen to provide the same number of possible configurations.
_________________
Economist GMAT Tutor
http://econgm.at/econgmat
(866) 292-0660
Manager
Manager
avatar
Joined: 11 Jan 2011
Posts: 57
GMAT 1: 680 Q44 V39
GMAT 2: 710 Q48 V40
GMAT ToolKit User
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 06 Nov 2013, 10:57
Thanks, that makes sense.
Economist GMAT Tutor Instructor
User avatar
Joined: 01 Oct 2013
Posts: 68
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 06 Nov 2013, 21:12
NvrEvrGvUp wrote:
Thanks, that makes sense.


I'm glad the explanation helped. Keep at it!
_________________
Economist GMAT Tutor
http://econgm.at/econgmat
(866) 292-0660
Intern
Intern
avatar
Joined: 11 Aug 2013
Posts: 29
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 08 Nov 2013, 21:20
5x2x2 =20, this is a mgmat questions. The end is slightly different.
Intern
Intern
avatar
B
Joined: 17 May 2015
Posts: 32
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 15 Jun 2015, 04:10
1
need great help to correct my steps/understanding:
I need to choose one of crust with 4 toppings.
so I need to choose 1 from 2 and 4 toppings from 5:
my work is as follows:
2/1! multiply 5x4x3x2 / 4!
= 2 / 1 x 5x4x3x2/4x3x2x1
= 2 x 5
= 10 choices
why my answer is wrong, need great help
is cheese and regular is also part of the equation.
Many thanks
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58453
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 15 Jun 2015, 04:51
1
1
apple08 wrote:
need great help to correct my steps/understanding:
I need to choose one of crust with 4 toppings.
so I need to choose 1 from 2 and 4 toppings from 5:
my work is as follows:
2/1! multiply 5x4x3x2 / 4!
= 2 / 1 x 5x4x3x2/4x3x2x1
= 2 x 5
= 10 choices
why my answer is wrong, need great help
is cheese and regular is also part of the equation.
Many thanks


There is one more piece of information: Mario's offers very pizza in extra-cheese as well as regular.

Mario's Pizza has two choices of crust: deep dish and thin-and-crispy. The restaurant also has a choice of 5 toppings: tomatoes, sausage, peppers, onions, and pepperoni. Finally, Mario's offers very pizza in extra-cheese as well as regular. If Linda's volleyball team decides to order a pizza with four toppings, how many different choices do the teammates have at Mario's Pizza?

Mario's Pizza:
2 choices of crust.
5 choices of toppings.
2 choices of cheese (extra-cheese or regular).

Linda decides to order a pizza with four toppings.

How many 4-topping pizzas are possible from 5? \(C^4_5=5\). But the pizza can have 2 different crusts and two different cheese, therefore the final answer is 5*2*2 = 20.
_________________
Intern
Intern
avatar
B
Joined: 17 May 2015
Posts: 32
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 17 Jun 2015, 00:03
Many thanks Bunuel really really appreciate it
Senior Manager
Senior Manager
User avatar
Joined: 15 Oct 2015
Posts: 299
Concentration: Finance, Strategy
GPA: 3.93
WE: Account Management (Education)
GMAT ToolKit User
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 15 Dec 2015, 04:57
Is this actually sub600? cos it's seems some users are as confused as I am. GMAT is really a foreign language tests.
was the level randomly assigned?
Senior Manager
Senior Manager
User avatar
Joined: 15 Oct 2015
Posts: 299
Concentration: Finance, Strategy
GPA: 3.93
WE: Account Management (Education)
GMAT ToolKit User
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 15 Dec 2015, 05:13
In the question there was mention of "crust". As I don't eat pizzas, and don't know the details of what constitute pizzas, I might need to get a lesson on pizza preparation.
but I guess from the problem, crust n toppings are stuffs for making pizzas. right? if you order a pizza with four toppings, how many choices do u have?
what happened to crust plz!
And finally, what does "finally... extra-cheese as well as regular" mean?
Pizza eating guys please explain.
Thanks.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13257
Re: Mario's Pizza has two choices of crust: deep dish and thin  [#permalink]

Show Tags

New post 25 Aug 2018, 12:44
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Bot
Re: Mario's Pizza has two choices of crust: deep dish and thin   [#permalink] 25 Aug 2018, 12:44
Display posts from previous: Sort by

Mario's Pizza has two choices of crust: deep dish and thin

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne