|
Author |
Message |
|
TAGS:
|
|
|
Intern
Joined: 03 Dec 2010
Posts: 44
|
An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
 16 Mar 2011, 10:05
1
This post received
KUDOS
D
E
Question Stats:
94% (01:41) correct
6% (00:35) wrong based on 17 sessions
HideShow timer Statistics
An instructor scored a student’s test of 50 questions by subtracting 2 times the number of incorrect answers from the number of correct answers. If the student answered all of the questions and received a score of 38, how many questions did that student answer correctly? (A) 19 (B) 38 (C) 41 (D) 44 (E) 46
Official Answer and Stats are available only to registered users. Register/ Login.
|
|
|
|
|
|
Manager
Joined: 03 Mar 2011
Posts: 90
Location: United States
GPA: 3.9
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
16 Mar 2011, 10:21
If x is the number of mistakes, then the score is (50-x)-2x=50-3x 50-3x=38 3x=12 x=4 So, the number of right answers is 50-4=46. The answer is E
_________________
If my post is useful for you not be ashamed to KUDO me!
Let kudo each other!
|
|
|
|
|
|
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7440
Location: Pune, India
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
16 Mar 2011, 18:17
Acer86 wrote: 12. An instructor scored a student’s test of 50 questions by subtracting 2 times the number of incorrect answers from the number of correct answers. If the student answered all of the questions and received a score of 38, how many questions did that student answer correctly?
(A) 19
(B) 38
(C) 41
(D) 44
(E) 46 Try and reason out the answers logically if possible... that will give you a lot of confidence... To understand the question, say Had the student answered all correctly, he would have scored 50. One mistake would have cost him 3 points : 49 points for correct answers, 2 points subtracted for 1 incorrect answer. This means every one incorrect answer leads to a loss of 3 points. Since he lost a total of 12 points, he must have had 4 questions incorrect. So he must have answered 46 questions correctly.
_________________
Karishma
Veritas Prep | GMAT Instructor
My Blog
Get started with Veritas Prep GMAT On Demand for $199
Veritas Prep Reviews
|
|
|
|
|
|
Director
Status: Impossible is not a fact. It's an opinion. It's a dare. Impossible is nothing.
Affiliations: University of Chicago Booth School of Business
Joined: 03 Feb 2011
Posts: 900
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
16 Mar 2011, 19:06
Yeah common sense tells me answer will be greater than 38. So only choices are d or e
Posted from my mobile device
|
|
|
|
|
|
SVP
Joined: 16 Nov 2010
Posts: 1664
Location: United States (IN)
Concentration: Strategy, Technology
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
17 Mar 2011, 02:20
x - #of correct answers y - # of incorrect answers x + y = 50 x - 2y = 38 so 3y = 12 => y = 4, so x = 46. Answer is E.
_________________
Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)
GMAT Club Premium Membership - big benefits and savings
|
|
|
|
|
|
Manager
Status: ==GMAT Ninja==
Joined: 08 Jan 2011
Posts: 242
Schools: ISB, IIMA ,SP Jain , XLRI
WE 1: Aditya Birla Group (sales)
WE 2: Saint Gobain Group (sales)
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
30 Mar 2011, 04:24
VeritasPrepKarishma wrote: Acer86 wrote: 12. An instructor scored a student’s test of 50 questions by subtracting 2 times the number of incorrect answers from the number of correct answers. If the student answered all of the questions and received a score of 38, how many questions did that student answer correctly?
(A) 19
(B) 38
(C) 41
(D) 44
(E) 46 Try and reason out the answers logically if possible... that will give you a lot of confidence... To understand the question, say Had the student answered all correctly, he would have scored 50. One mistake would have cost him 3 points : 49 points for correct answers, 2 points subtracted for 1 incorrect answer. This means every one incorrect answer leads to a loss of 3 points. Since he lost a total of 12 points, he must have had 4 questions incorrect. So he must have answered 46 questions correctly. Karishma your way of handeling problems is awesome this is infact real GMAT approach hats off to you  
_________________
WarLocK
_____________________________________________________________________________
The War is oNNNNNNNNNNNNN for 720+
see my Test exp here http://gmatclub.com/forum/my-test-experience-111610.html
do not hesitate me giving kudos if you like my post. 
|
|
|
|
|
|
Manager
Joined: 04 Aug 2011
Posts: 51
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
07 Aug 2011, 05:05
An instructor scored a student's test of 50 questions by subtracting 2 times the number of incorrect answers from the number of correct answers. If the student answered all of the questions and received a score of 38, how many questions did that student answer correctly?
a) 19
b) 38
c) 41
d) 44
e) 46
|
|
|
|
|
|
Intern
Joined: 18 Jun 2011
Posts: 14
WE: Information Technology (Investment Banking)
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
07 Aug 2011, 07:21
1
This post received
KUDOS
Try plugin answers
A. 19-2(31) != 38
B. 38-2(12) !=38
C. 41-2(9) !=38
D. 44-2(6) !=38
E. 46-2(4) =38
Ans E.
|
|
|
|
|
|
Intern
Joined: 28 Jun 2011
Posts: 7
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
08 Aug 2011, 17:59
Total questions: 50
Score per correct: 1
Total scores:50
Scores received:38
Scores missed:50-38=12
Incorrect:12/2=6
Therefore, number of questions students answered correctly=50-6=44
I know the OA is E. Please explain.
thanks.
|
|
|
|
|
|
Manager
Joined: 04 Aug 2011
Posts: 51
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
08 Aug 2011, 22:24
Do you mean the answers like following? A. 19-2(31) != -43, so it is wrong, because the score is 38. B. 38-2(12) != 14, so it is wrong again. C. 41-2(9) != 23, so it is wrong D. 44-2(6) != 32, wrong. E. 46-2(4) =38, correct because that's the score. Does your explaination mean above? Try plugin answers A. 19-2(31) != 38 B. 38-2(12) !=38 C. 41-2(9) !=38 D. 44-2(6) !=38 E. 46-2(4) =38 vinayreguri wrote: Try plugin answers
A. 19-2(31) != 38
B. 38-2(12) !=38
C. 41-2(9) !=38
D. 44-2(6) !=38
E. 46-2(4) =38
Ans E.
|
|
|
|
|
|
Manager
Joined: 04 Jun 2011
Posts: 183
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
09 Aug 2011, 10:34
if u need it the mathematical style
let c = no. of correct answers
w = no. of wrong answers.
we know total questions = 50
==> c+w = 50 => c = 50-w --------- (1)
the teacher removed 2 times wrong answers from correct answer and gave the score as 38
==> c - 2w = 38 ----------- (2)
substitute (1) in (2)
50 - w - 2w = 38 => 50 - 38 = 3 w
=> w = 4 Therefore no. of wrong ans = 4 which implies no. of right = 46, E
|
|
|
|
|
|
Current Student
Joined: 02 Aug 2011
Posts: 44
Location: Canada
Concentration: Finance, Healthcare
GPA: 3.4
WE: Analyst (Consulting)
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
09 Aug 2011, 13:12
Student got 38 points, he had to get well over 40 correct since if he got 40 he'd have gotten only 30 points. Test 44 and 46.
44 - 2*6 = 32 --> nope
46 - 2*4 = 38 --> yay
E
|
|
|
|
|
|
Manager
Joined: 04 Aug 2011
Posts: 51
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
09 Aug 2011, 20:18
That's what I mean in my previous reply. far257 wrote: Student got 38 points, he had to get well over 40 correct since if he got 40 he'd have gotten only 30 points. Test 44 and 46.
44 - 2*6 = 32 --> nope
46 - 2*4 = 38 --> yay
E
|
|
|
|
|
|
Director
Joined: 01 Feb 2011
Posts: 755
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
21 Aug 2011, 20:08
let x be number of correct questions . => 50-x is the number of incorrect questions.
so the professor scored the questions as x + 2(50-x).
given x + 2(50-x) = 38
=> x= 46
Answer is E.
|
|
|
|
|
|
Manager
Joined: 20 Aug 2011
Posts: 146
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2 [#permalink]
Show Tags
21 Aug 2011, 23:26
let x be no. of correct answers since all questions are attempted no. of incorrect answers =50-x according to given conditions, x-2*(50-x)=38 3x=138 x=46
_________________
Hit kudos if my post helps you.
You may send me a PM if you have any doubts about my solution or GMAT problems in general.
|
|
|
|
|
|
|
Re: An instructor scored a student’s test of 50 questions by subtracting 2
[#permalink]
21 Aug 2011, 23:26
|
|
|
|
|
|
|
|
|
|
|
|
|
1
