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

 It is currently 16 Oct 2019, 15:30 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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.  In a certain learning experiment, each participant had three trials an

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

Hide Tags

Board of Directors D
Joined: 01 Sep 2010
Posts: 3397
In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

1
Top Contributor
19 00:00

Difficulty:   45% (medium)

Question Stats: 72% (02:35) correct 28% (02:28) wrong based on 915 sessions

HideShow timer Statistics

In a certain learning experiment, each participant had three trials and was assigned, for each trial, a score of either -2, -1, 0, 1, or 2. The participant's final score consisted of the sum of the first trial score, 2 times the second trial score, and 3 times the third trial score. If Anne received scores of 1 and -1 for her first two trials, not necessarily in that order, which of the following could NOT be her final score?

A. -4

B. -2

C. 1

D. 5

E. 6

_________________
Intern  B
Joined: 24 Feb 2017
Posts: 35
Schools: CBS '20 (S)
GMAT 1: 760 Q50 V42 In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

33
11
bfistein wrote:
Took me 03:17 to solve, did it the same way as above. Seems like one of those questions that is just going to take a long-ish time to solve, albeit it is fairly simple.

Not really. There's no need to calculate each individual sums.

2 possible scores for the first two trials 1,-1. Let 3rd trial score = x.

Total score can be 3x+1 or 3x-1. Can never be a multiple of 3. So, 6 (or in that case even -6,-3,0,3,6) can't come.
General Discussion
Manager  S
Joined: 23 May 2017
Posts: 235
Concentration: Finance, Accounting
WE: Programming (Energy and Utilities)
Re: In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

2
Score in first trial = x
Score in 2nd trial = y
Score in 3rd trial = z

allowed values for x , y and z are -2, -1, 0, 1, 2

final score = x + 2y + 3z

given 2 scores are 1 and -1

so x = 1 or y = 1 or z = 1
and x = -1 or y = -1 or z = -1

sum can be
==> 1 + (2 * -1) + 3z ==> 3z - 1 ==> equation 1
==> 1 + 2y + ( 3* -1) ==> 2y - 2 ==> equation 2
==> -1 + (2 * 1) + 3z ==> 3z + 1 ===> equation 3

for z = -2 equation1 = -6 - 1= -7 and equation 3 = -6 + 1 = -5
for z = -1 equation1 = -3 - 1= -4 and equation 3 = -3 + 1 = -2
for z = 0 equation1 = 0 - 1 = -1 and equation 3 = 0 + 1 = 1
for z = 1 equation1 = 3 - 1 = 2 and equation 3 = 3 + 1 = 4
for z = 2 equation1 = 6 - 1 = 5 and equation 3 = 6 + 1 = 7

for y = -2 equation 2 = 2y - 2 = -4 - 2 = -6
for y = -1 equation 2 = 2y - 2 = -2 - 2 = -4
for y = 0 equation 2 = 2y - 2 = - 2 = -2
for y = 1 equation 2 = 2y - 2 = 2 - 2 = 0
for y = 2 equation 2 = 2y - 2 = 4 - 2 = 2

Among the answer choice all except 6 ( choice E ) can be the final score
_________________
If you like the post, please award me Kudos!! It motivates me
Senior SC Moderator V
Joined: 22 May 2016
Posts: 3544
In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

2
carcass wrote:
In a certain learning experiment, each participant had three trials and was assigned, for each trial, a score of either -2, -1, 0, 1, or 2. The participant's final score consisted of the sum of the first trial score, 2 times the second trial score, and 3 times the third trial score. If Anne received scores of 1 and -1 for her first two trials, not necessarily in that order, which of the following could NOT be her final score?

A. -4

B. -2

C. 1

D. 5

E. 6

1. There are two cases for the total value of first two trials' scores of 1 and -1.

Case 1
Trial 1 = -1. Trial 2 = 1, with weighted score of 2.

-1 + 2 = 1

Case 2
Trial 1 = 1. Trial 2 = -1, with weighted score of -2.

1 + (-2) = -1

2. Add Trial 3 weighted score, 3C, to 1 or -1

Possible values, C, for Trial 3 are -2, -1, 0, 1, or 2

Which answer choice can we not achieve by addition or subtraction of 3C in combination with either 1 or -1?

A. -4. Possible. C is -1, 3C is -3.
-1 - 3 = -4. Reject

B. -2. Possible. C is -1, 3C is -3.
1 - 3 = -2. Reject

C. 1. Possible. C is 0, 3C is 0.
1 + 0 = 1. Reject

D. 5. Possible. C is 2, 3C is 6.
-1 + 6 = 5. Reject

E. 6. Impossible by default. And there is no way to get +5 (to add to Case 1) or +7 (to add to Case 2) from 3 or a multiple of 3.

_________________
SC Butler has resumed! Get two SC questions to practice, whose links you can find by date, here.

Choose life.
Senior PS Moderator V
Joined: 26 Feb 2016
Posts: 3341
Location: India
GPA: 3.12
Re: In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

1
There are 2 possibilities
Case 1: Trial score 1(x) : 1, Trial score 2(y) : -1
(Sum = 1*1 + 2*-1 = -1)
Case 2: Trial score 1(x) : -1, Trial score 2(y) : 1
(Sum = 1*-1 + 2*1 = 1)

As for the third score, there are 5 possibilities each in case 1 and case 2
-2,-1,0,1,2 which has to multiplied by 3 and added to the previous sum(from both cases)
The numbers which has to be added to attain the possible sums are -6,-3,0,3,6.

Possible sums in case 1 : -7,-4,-1,2,5
Possible sums in case 2 : -5,-2,1,4,7

The only possible sum which is not part of this list is 6(Option E)
_________________
You've got what it takes, but it will take everything you've got
Intern  B
Joined: 12 Jul 2017
Posts: 2
Re: In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

Took me 03:17 to solve, did it the same way as above. Seems like one of those questions that is just going to take a long-ish time to solve, albeit it is fairly simple.
Target Test Prep Representative D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8069
Location: United States (CA)
Re: In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

2
carcass wrote:
In a certain learning experiment, each participant had three trials and was assigned, for each trial, a score of either -2, -1, 0, 1, or 2. The participant's final score consisted of the sum of the first trial score, 2 times the second trial score, and 3 times the third trial score. If Anne received scores of 1 and -1 for her first two trials, not necessarily in that order, which of the following could NOT be her final score?

A. -4

B. -2

C. 1

D. 5

E. 6

If Anne received 1 for her first trial and -1 for her second, then the sum of her first two trials is 1 + 2(-1) = 1 + -2 = -1.

If Anne received -1 for her first trial and 1 for her second, then the sum of her first two trials is -1 + 2(1) = -1 + 2 = 1.

Let’s analyze each answer choice:

A) -4

If the sum of the first two trials is -1 and the third trial is -1, then the sum can be -1 + 3(-1) = -4.

B) -2

If the sum of the first two trials is 1 and the third trial is -1, then the sum can be 1 + 3(-1) = -2.

C) 1

If the sum of the first two trials is 1 and the third trial is 0, then the sum can be 1 + 3(0) = 1.

D) 5

If the sum of the first two trials is -1 and the third trial is 2, then the sum can be -1 + 3(2) = 5.

E) 6

We see there is no way to get a sum of 6.

_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Manager  B
Joined: 21 Jun 2017
Posts: 82
Re: In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

carcass wrote:
In a certain learning experiment, each participant had three trials and was assigned, for each trial, a score of either -2, -1, 0, 1, or 2. The participant's final score consisted of the sum of the first trial score, 2 times the second trial score, and 3 times the third trial score. If Anne received scores of 1 and -1 for her first two trials, not necessarily in that order, which of the following could NOT be her final score?

A. -4

B. -2

C. 1

D. 5

E. 6

Final Score = (S1) + (S2 x 2) + (S3 x 3)
given s1 and s2 = 1 or -1
1 + (-2) + 6 = 5 so eliminate 5
1 + (-2) + (-3) = 4 so eliminate 4
-1 + (2) + (-3) = -2
-1 + 2 = 0 = 1 eliminate 1

we are left with 6

Current Student S
Joined: 01 Dec 2016
Posts: 104
Concentration: Finance, Entrepreneurship
GMAT 1: 650 Q47 V34 WE: Investment Banking (Investment Banking)
Re: In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

For this question, i believe the simplest way is to test the answer choices.
From the stem, it flows that her score, before the last trial, will be 1 or -1.
To get -4 as final score she must have 4 or -1. This is possible if she gets -1 in the last trial.
Keep on testing, we see that the answer choices A through D work.
But E does not work: to have 6 as final score, she must get a score of 5 or 7 in the last trial. both value are not multiple of 3.
_________________
What was previously considered impossible is now obvious reality.
In the past, people used to open doors with their hands. Today, doors open "by magic" when people approach them
Intern  B
Joined: 26 Jul 2018
Posts: 14
Location: India
Schools: ISB
Re: In a certain learning experiment, each participant had three trials an  [#permalink]

Show Tags

How do I do this in 2mins?

ScottTargetTestPrep wrote:
carcass wrote:
In a certain learning experiment, each participant had three trials and was assigned, for each trial, a score of either -2, -1, 0, 1, or 2. The participant's final score consisted of the sum of the first trial score, 2 times the second trial score, and 3 times the third trial score. If Anne received scores of 1 and -1 for her first two trials, not necessarily in that order, which of the following could NOT be her final score?

A. -4

B. -2

C. 1

D. 5

E. 6

If Anne received 1 for her first trial and -1 for her second, then the sum of her first two trials is 1 + 2(-1) = 1 + -2 = -1.

If Anne received -1 for her first trial and 1 for her second, then the sum of her first two trials is -1 + 2(1) = -1 + 2 = 1.

Let’s analyze each answer choice:

A) -4

If the sum of the first two trials is -1 and the third trial is -1, then the sum can be -1 + 3(-1) = -4.

B) -2

If the sum of the first two trials is 1 and the third trial is -1, then the sum can be 1 + 3(-1) = -2.

C) 1

If the sum of the first two trials is 1 and the third trial is 0, then the sum can be 1 + 3(0) = 1.

D) 5

If the sum of the first two trials is -1 and the third trial is 2, then the sum can be -1 + 3(2) = 5.

E) 6

We see there is no way to get a sum of 6. Re: In a certain learning experiment, each participant had three trials an   [#permalink] 18 Apr 2019, 11:27
Display posts from previous: Sort by

In a certain learning experiment, each participant had three trials an

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne  