MCA
Exam
Numerical Ability
Algebra
In an examination,a student gets 5 marks for every right answer and loses 2 marks for every wrong answer.If he answers 50 questions and get 124 marks, how many are correct answers he attempted?
Read Solution (Total 7)
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- Let us assume he answered 'r' right answers and 'w' wrong answers.Then acc.. to given question, the equations would be,
5r-2w = 124 // as for right answer 5 mrks and wrng answer -2 mrk
r+w = 50 // total attempted questions
solving above eqns,we get r = 32
32 are correct answers - 10 years agoHelpfull: Yes(6) No(1)
- let noof correct ans as x and wrong answers as y.
x+y=50 (total noof qstns answered)
5x-2y=124
by solving above two qstns we get x=32,y=18
he attempted 32 correct answers - 10 years agoHelpfull: Yes(0) No(0)
- let number of correct question done=x,therefore,no.of wrong questions done=50-x,according to question,total mark=124,i.e 5x-2(50-x)=124
=>x=32 - 10 years agoHelpfull: Yes(0) No(0)
- wrong answer=y
correct answer=x
total x+y=50;
now he wrote some questions correct and some of wrong he get 124 marks
so 5x-2y=124
solve 2 eqns then we get x=32
- 10 years agoHelpfull: Yes(0) No(0)
- 25 ans he attempt corrct
- 9 years agoHelpfull: Yes(0) No(0)
- lets x correct answer and 50-x wrong answer then
x*5-(50-x)*2=124
5x-100+2x=124
7x=224
x=32
- 9 years agoHelpfull: Yes(0) No(0)
- let x = no. of the correct answer and y= no. of incorrect answer
then x+y=50 => x=50-y
for each right answer, the student gets 5 marks, and for the wrong answer loses 2 marks.
=> 5x-2y=124
by putting x=50-y
=>5(50-y)-2y=124
250-5y-2y=124
-7y=124-250
-7y=-126
y=126/7
y=18
now putting y=18 on x=50-y
=>x=32
=> The student attempted 32 questions correct - 3 years agoHelpfull: Yes(0) No(0)
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