Q6 A boy gets 3 marks for each correct sum and loses 2 marks for each incorrect sum .He does 24 sums and obtains 37 marks .The number of correct sums
Roseta:
Dear friend ur question is wrong somewhere
Bcoz the no. of marks reduced should be even as negative mark is 2 but the number of marks reduced is 35. That means ur question is wrong somewhere. Plz recheck ur question.
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Let the number of correct questions answered be 'a'
Let the number of wrong questions answered be 'b'
Given that number of sums answered totally are 24
i.e a+b=24------------(1)
The total marks of correct answers are 3a
The total marks of wrong answers are 2b
Since the marks of wrong answers are deducted from marks of correct answers, the expression is 3a-2b
The total number of marks after deduction is 37
i.e 3a-2b=37--------(2)
(1)*2 => 2a+2b=48-------(3)
Solve (3) and (2)
2a+2b=48
3a-2b=37
---------------
5a=85
---------------
a=17
The total number of correct answered questions are 17
Let the number of wrong questions answered be 'b'
Given that number of sums answered totally are 24
i.e a+b=24------------(1)
The total marks of correct answers are 3a
The total marks of wrong answers are 2b
Since the marks of wrong answers are deducted from marks of correct answers, the expression is 3a-2b
The total number of marks after deduction is 37
i.e 3a-2b=37--------(2)
(1)*2 => 2a+2b=48-------(3)
Solve (3) and (2)
2a+2b=48
3a-2b=37
---------------
5a=85
---------------
a=17
The total number of correct answered questions are 17
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