Last visit was: 26 Apr 2024, 07:59 It is currently 26 Apr 2024, 07:59

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
SORT BY:
Date
Math Expert
Joined: 02 Sep 2009
Posts: 92940
Own Kudos [?]: 619178 [3]
Given Kudos: 81609
Send PM
RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11181
Own Kudos [?]: 31950 [3]
Given Kudos: 291
Send PM
SVP
SVP
Joined: 20 Mar 2014
Posts: 2362
Own Kudos [?]: 3626 [1]
Given Kudos: 816
Concentration: Finance, Strategy
GMAT 1: 750 Q49 V44
GPA: 3.7
WE:Engineering (Aerospace and Defense)
Send PM
Math Expert
Joined: 02 Sep 2009
Posts: 92940
Own Kudos [?]: 619178 [0]
Given Kudos: 81609
Send PM
Re: Three students were given three tests, the results of the first two te [#permalink]
Expert Reply
Bunuel wrote:

Three students were given three tests, the results of the first two tests are shown above. Student 1 and Student 3 received equal scores on Test 3. As a result, Student 1’s average (arithmetic mean) score over the three tests was 50 percent higher than Student 3’s average. What was the score Students 1 and 3 received on Test 3?

A. 33
B. 34
C. 35
D. 36
E. 39


Kudos for a correct solution.

Attachment:
tests.gif


800score Official Solution:

Let x be the score that both Student 1 and Student 3 received on Test 3.
Since Student 1's average is 50% higher than Student 3's average, Student 1's average is 1.5 times that of Student 3.
The average for Student 1 is (30 + 50 + x)/3, and the average for Student 3 is (14 + 28 + x)/3.

So we can solve for x as follows:
(30 + 50 + x)/3 = ((14 + 28 + x)/3) × 1.5
(80 + x)/3 = ((42 + x)/3) × 1.5
(80 + x)/3 = (63 + 1.5x)/3
80 + x = 63 + 1.5x
17 = 0.5x
x = 34.

The correct answer is choice (B).
Manager
Manager
Joined: 06 Dec 2016
Posts: 196
Own Kudos [?]: 57 [0]
Given Kudos: 10
Send PM
Re: Three students were given three tests, the results of the first two te [#permalink]
I got the answer by process elimination
Answer B

The average of student 1 with 34 is 38
The average of student 3 with 34 is 25 1/3

25 1/3 x 1 1/2
38

The answer has to be B. :-D
Process elimination can be a life saver sometime.
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18761
Own Kudos [?]: 22056 [0]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: Three students were given three tests, the results of the first two te [#permalink]
Expert Reply
Bunuel wrote:
Three students were given three tests, the results of the first two tests are shown above. Student 1 and Student 3 received equal scores on Test 3. As a result, Student 1’s average (arithmetic mean) score over the three tests was 50 percent higher than Student 3’s average. What was the score Students 1 and 3 received on Test 3?

A. 33
B. 34
C. 35
D. 36
E. 39


We can let x = the score for student 1 and student 3 on test number 3. Thus, the average score for student 1 is:

(30 + 50 + x)/3 = (80 + x)/3

The average for student 3 is:

(14 + 28 + x)/3 = (42 + x)/3

Student 1’s average (arithmetic mean) score over the three tests was 50 percent higher than Student 3’s average. Using that fact, we can create the following equation to determine x:

(80 + x)/3 = 1.5[(42 + x)/3]

(80 + x) = 1.5(42 + x)

80 + x = 63 + 1.5x

17 = 0.5x

34 = x

Answer: B
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 32685
Own Kudos [?]: 822 [0]
Given Kudos: 0
Send PM
Re: Three students were given three tests, the results of the first two te [#permalink]
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: Three students were given three tests, the results of the first two te [#permalink]
Moderators:
Math Expert
92933 posts
Senior Moderator - Masters Forum
3137 posts

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