An online exam has 100 questions. A candidate gets 3 points for every correct answer, and -9 for every wrong answer, and questions cannot be skipped. How many correct answers must a candidate have to score 240
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__________________________________________________________
Question:
An online exam has 100 questions. A candidate gets 3 points for every correct answer, and -9 for every wrong answer, and questions cannot be skipped. How many correct answers must a candidate have to score 240
Solution
Lets consider the no of correct ans given by the students to be x.
Lets consider the no of incorrect ans given by the students to be y.
So from the above data we can make two equations.
The first data says that
A candidate gets 3 points for every correct answer, and -9 for every wrong answer, and questions cannot be skipped. and he scored 240
So the equation for this data becomes
3x - 9y = 240 --------- 1
x -3y = 80 ----------- 2
Second data says that
An online exam has 100 questions.
So the equation for it becomes
x + y = 100 ------3
x =100-y --------4
So now solving equations
Substitute 3 in 2
That is
100 - y - 3y = 80
4y = 20
y = 5
so x = 95
So the number of correct ans given by the student is 95.
the number of incorrect ans given by the student is 5.
____________________________________________________
hope this helps
regards
__________________________________________________________
Question:
An online exam has 100 questions. A candidate gets 3 points for every correct answer, and -9 for every wrong answer, and questions cannot be skipped. How many correct answers must a candidate have to score 240
Solution
Lets consider the no of correct ans given by the students to be x.
Lets consider the no of incorrect ans given by the students to be y.
So from the above data we can make two equations.
The first data says that
A candidate gets 3 points for every correct answer, and -9 for every wrong answer, and questions cannot be skipped. and he scored 240
So the equation for this data becomes
3x - 9y = 240 --------- 1
x -3y = 80 ----------- 2
Second data says that
An online exam has 100 questions.
So the equation for it becomes
x + y = 100 ------3
x =100-y --------4
So now solving equations
Substitute 3 in 2
That is
100 - y - 3y = 80
4y = 20
y = 5
so x = 95
So the number of correct ans given by the student is 95.
the number of incorrect ans given by the student is 5.
____________________________________________________
hope this helps
regards
vaibhavsaraswat:
95
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