A teacher grades students' tests by subtracting twice the number of incorrect responses from the number of correct responses. If Student A answers each of the 100 questions on her test and receives a score of 73, how many questions did Student A answer correctly?
A. 55
B. 60
C. 73
D. 82
E. 91
The OA is E.
I get the solution to this PS question as follows,
Let the number of correct responses be = x
So the number of wrong responses = 100 - x
x - 2(100 - x) = 73
x - 200 + 2x = 73
3x = 273
x = 91
Option E.
A teacher grades students' tests by subtracting twice the
This topic has expert replies
-
- Moderator
- Posts: 2205
- Joined: Sun Oct 15, 2017 1:50 pm
- Followed by:6 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
-
- Legendary Member
- Posts: 2214
- Joined: Fri Mar 02, 2018 2:22 pm
- Followed by:5 members
Let the number of correct response= x
number of incorrect responses= 100 x
Question says
x-2 (100-x)=73 (subtracting twice of incorrect from correct)
$$\frac{3x}{3}=\frac{273}{3};$$
$$x=91$$
hence option E is the correct answer
number of incorrect responses= 100 x
Question says
x-2 (100-x)=73 (subtracting twice of incorrect from correct)
$$\frac{3x}{3}=\frac{273}{3};$$
$$x=91$$
hence option E is the correct answer
GMAT/MBA Expert
- [email protected]
- Elite Legendary Member
- Posts: 10392
- Joined: Sun Jun 23, 2013 6:38 pm
- Location: Palo Alto, CA
- Thanked: 2867 times
- Followed by:511 members
- GMAT Score:800
Hi All,
This question can be solved by TESTing THE ANSWERS.
We're given a few facts about a particular test and a student who took that test:
1) The score on the test is generated by subtracting TWICE the number of incorrect responses from the number of correct responses.
2) A student answered ALL 100 questions.
3) That student earned a score of 73.
We're asked for the number of questions that the student answered correctly.
Since the number of incorrect answers is DOUBLED before that number is subtracted, it would clearly take MORE than 73 correct answers to get a score of 73 (since 27 wrong answers would end up leading to a score of 73 - 2(27) = 19).
Let's TEST Answer D: 82 correct
With 82 correct answers, we would have a score of 82- 2(18) = 46. This is TOO SMALL (it's supposed to be a score of 73). The only way to score HIGHER than 46 is with MORE correct answers. There's only one answer left...
Final Answer: E
GMAT assassins aren't born, they're made,
Rich
This question can be solved by TESTing THE ANSWERS.
We're given a few facts about a particular test and a student who took that test:
1) The score on the test is generated by subtracting TWICE the number of incorrect responses from the number of correct responses.
2) A student answered ALL 100 questions.
3) That student earned a score of 73.
We're asked for the number of questions that the student answered correctly.
Since the number of incorrect answers is DOUBLED before that number is subtracted, it would clearly take MORE than 73 correct answers to get a score of 73 (since 27 wrong answers would end up leading to a score of 73 - 2(27) = 19).
Let's TEST Answer D: 82 correct
With 82 correct answers, we would have a score of 82- 2(18) = 46. This is TOO SMALL (it's supposed to be a score of 73). The only way to score HIGHER than 46 is with MORE correct answers. There's only one answer left...
Final Answer: E
GMAT assassins aren't born, they're made,
Rich
GMAT/MBA Expert
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7223
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
We can create the following equations, in which c = the number of correct responses and w = the number of incorrect responses:BTGmoderatorLU wrote:A teacher grades students' tests by subtracting twice the number of incorrect responses from the number of correct responses. If Student A answers each of the 100 questions on her test and receives a score of 73, how many questions did Student A answer correctly?
A. 55
B. 60
C. 73
D. 82
E. 91
c + w = 100
w = 100 - c
and
c - 2w = 73
Substituting, we have:
c - 2(100 - c) = 73
c - 200 + 2c = 73
3c = 273
c = 91
Answer: E
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews