It is currently 20 Nov 2018, 03:32

### 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

# Contestants at a baking contest must use between 5 and 8 of

Author Message
TAGS:
GMAT Club Legend
Joined: 07 Jun 2014
Posts: 4720
GRE 1: Q167 V156
WE: Business Development (Energy and Utilities)
Followers: 91

Kudos [?]: 1622 [0], given: 385

Contestants at a baking contest must use between 5 and 8 of [#permalink]  30 Dec 2017, 13:21
Expert's post
00:00

Question Stats:

80% (01:03) correct 20% (01:13) wrong based on 15 sessions
Contestants at a baking contest must use between 5 and 8 of 10 possible ingredients.

 Quantity A Quantity B The number of ingredients that must be used to get the smallest possible number of different combinations The number of ingredients that must be used to get the largest possible number of different combinations Quantity A is greater.

A. Quantity A is greater.
B. Quantity B is greater.
C. The two quantities are equal.
D. The relationship cannot be determined from the information given.

Drill 1
Question: 12
Page: 561
[Reveal] Spoiler: OA

_________________

Sandy
If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test

Intern
Joined: 05 Jan 2018
Posts: 32
Followers: 0

Kudos [?]: 16 [2] , given: 8

Re: Contestants at a baking contest must use between 5 and 8 of [#permalink]  06 Jan 2018, 04:41
2
KUDOS
Ans A.

To get smaller combinations, 8 out of 10 ingredients need to be used.

nCr for 8 ingredients = 45 combinations (Quantity A = 8)
nCr for 5 ingredients = 252 combination (Quantity B = 5)
GMAT Club Legend
Joined: 07 Jun 2014
Posts: 4720
GRE 1: Q167 V156
WE: Business Development (Energy and Utilities)
Followers: 91

Kudos [?]: 1622 [0], given: 385

Re: Contestants at a baking contest must use between 5 and 8 of [#permalink]  08 Jan 2018, 16:15
Expert's post
Explanation

You are forming groups where order doesn’t matter, so use the combination formula.

If you use 5 ingredients, then there are: $$\frac{10}{5}\times\frac{9}{4}\times\frac{8}{3}\times\frac{7}{2}\times\frac{6}{1}=252$$ different combinations.

If you use 6 ingredients there are $$\frac{10}{6}\times\frac{9}{5}\times\frac{8}{4}\times\frac{7}{3}\times\frac{6}{2}\times\frac{5}{1}=210$$ combinations, if you use 7 there are $$\frac{10}{7}\times\frac{9}{6}\times\frac{8}{5}\times\frac{7}{4}\times\frac{6}{3}\times\frac{5}{2}\times\frac{4}{1}=120$$, and if you use 8 there are $$\frac{10}{8}\times\frac{9}{7}\times\frac{8}{6}\times\frac{7}{5}\times\frac{6}{4}\times\frac{5}{3}\times\frac{4}{2}\times\frac{3}{1}=45$$.

Thus, Quantity A is 8, and Quantity B is 5, choice A.
_________________

Sandy
If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test

Director
Joined: 07 Jan 2018
Posts: 540
Followers: 4

Kudos [?]: 466 [0], given: 83

Re: Contestants at a baking contest must use between 5 and 8 of [#permalink]  10 Jan 2018, 01:05
Hello sandy

In questions such as between so and so value such as 5 and 8 is this always the case that the two values are inclusive?
_________________

This is my response to the question and may be incorrect. Feel free to rectify any mistakes

Moderator
Joined: 18 Apr 2015
Posts: 4916
Followers: 74

Kudos [?]: 980 [1] , given: 4506

Re: Contestants at a baking contest must use between 5 and 8 of [#permalink]  10 Jan 2018, 02:07
1
KUDOS
Expert's post
In not is specified you should consider 5 and 8 included. I.E the range is not from 6 to 7 but 5 to 8.

This is a good question for practice but not the top notch. An official question must be included in the statement if they should be considered or not. To clear all the possible confusion.

Regards
_________________
Intern
Joined: 04 Mar 2018
Posts: 24
Followers: 0

Kudos [?]: 11 [1] , given: 5

Re: Contestants at a baking contest must use between 5 and 8 of [#permalink]  09 Mar 2018, 03:28
1
KUDOS
Whenever it is written from a to b, both ends must be included, but when it is written between a and b, ends are not included, its b-a-1 no of terms. Therefore, in this case its just 6 and 7.
If anyone says this then he or she is wrong. If not mentioned whether it is inclusive or not, it must be assumed inclusive.
Re: Contestants at a baking contest must use between 5 and 8 of   [#permalink] 09 Mar 2018, 03:28
Display posts from previous: Sort by