My Profile Logout

Test's Subscription Expires:

My Follow Feed Kudos My Error Log

Messages and Replies

Settings Mark All Read

See All

Applicant Notifications

Settings Mark All Read

See All

Global notifications

Settings Mark All Read

See All

1/3 of the cookies in a jar are chocolate chip, 2/3 of the remaining

Sort by Date

Sort by Kudos

Author

Message

TAGS:

Hide Tags

Find Similar Topics

Math Expert

Joined: 02 Sep 2009

Posts: 58320

1/3 of the cookies in a jar are chocolate chip, 2/3 of the remaining [#permalink]

Show Tags

23 Jan 2019, 00:54

00:00

Difficulty:

25% (medium)

Question Stats:

77% (01:52) correct

23% (02:25) wrong

based on 54 sessions

HideShow timer Statistics

1/3 of the cookies in a jar are chocolate chip, 2/3 of the remaining cookies are peanut butter, and the rest of the cookies are white chocolate. If 20 cookies are white chocolate, how many cookies are in the jar?

A 40

B 60

C 70

D 90

E 100

Spoiler: OA

_________________

What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Signature Read More

Joined: 31 Oct 2013

Posts: 1473

Concentration: Accounting, Finance

GPA: 3.68

WE: Analyst (Accounting)

Re: 1/3 of the cookies in a jar are chocolate chip, 2/3 of the remaining [#permalink]

Show Tags

23 Jan 2019, 01:15

Bunuel wrote:

let there are x cookies in the jar.

chocolate chip = 1/3*x = x/3.

Remaining cookies = 2x/3.

PB = 2x/3 * 2/3 = 4x/9.

Remaining cookies = 2x/3 - 4x/9 = 2x /9.

2x/9 = white chips.

2x/9 = 20

x = 90.

D is the correct answer.

Intern

Joined: 10 Feb 2018

Posts: 31

GMAT 1: 550 Q46 V20

1/3 of the cookies in a jar are chocolate chip, 2/3 of the remaining [#permalink]

Show Tags

23 Jan 2019, 01:58

IMO D ie 90 cookies in the jar

chocolate chip cookies = 1/3
So remaining cookies =2/3

Peanut butter cookies=2/3 of remaining
ie 2/3*2/3=4/9 of total is PB

Remaining cookies= 1-(1/3+4/9)=1-7/9= 2/9 of total cookies

2/9 of total cookies = 20

Therefore Total cookies = 90.

GMAT Club Legend

Joined: 18 Aug 2017

Posts: 4987

Location: India

Concentration: Sustainability, Marketing

GPA: 4

WE: Marketing (Energy and Utilities)

Re: 1/3 of the cookies in a jar are chocolate chip, 2/3 of the remaining [#permalink]

Show Tags

23 Jan 2019, 08:08

Bunuel wrote:

we can solve < 30 seconds this quesiton
given x/3 are chocolate cookies
so all options except b & d are valid

further we can notice that option b ends up being a fraction where as d stands as an integer

so IMO D is correct..
_________________

If you liked my solution then please give Kudos. Kudos encourage active discussions.

Signature Read More

Target Test Prep Representative

Status: Founder & CEO

Affiliations: Target Test Prep

Joined: 14 Oct 2015

Posts: 8043

Location: United States (CA)

Re: 1/3 of the cookies in a jar are chocolate chip, 2/3 of the remaining [#permalink]

Show Tags

27 Jan 2019, 19:23

Bunuel wrote:

We can let the total number of cookies = n. We see that n/3 cookies are chocolate chip. The remaining number of cookies is (2/3) x n = 2n/3. We know that 2/3 of these 2n/3 cookies are peanut butter, so (2/3)x(2n/3) are peanut butter. We can now create the equation:

n/3 + 2/3(2n/3) + 20 = n

n/3 + 4n/9 + 20 = n

Multiplying by 9, we have:

3n + 4n + 180 = 9n

180 = 2n

90 = n

Answer: D
_________________