In an competitive examination there were 60 questions.The correct answer would carry 2 marks and 1 mark would be subtracted.Yaahwant had attempted all the questions and he got total 90 marks.Then how many qst he went wrong??
Solve this sum in 'Linear equation in two variables form' pllzzzzzzz
Answers
Answer:
Step-by-step explanation:
Let No of Correct answers be x
Let No. of wrong answers be y
Let No. of Unattempted question be z
Given that He had attempted all the questions that means z = 0
Now, Total number of questions (x+y+z)=60
⇒x+y=60 _________ (i)
No. of marks awarded for each correct answers = 2
Total Number of marks for correct answers = (No. of corret answers)*(Marks awarded for each correct answer)
Total Number of marks for correct answers = x*2=2x
Similarly No. of marks awarded for each wrong answers = -1
Similarly No. of marks awarded for each wrong answers = (No. of wrong answers)*(Marks awarded for each wrong answer)
Total Number of marks for wrong answers = y*(-1)=-y
Total marks 90 =
(No. of marks awarded for each correct answers) + (Total Number of marks for wrong answers)
⇒ 90 = 2x-y _________ (ii)
From (i) we get y = 90-x
Substituting Value of y above in (ii)
⇒90 = 2x-(90-x)
⇒90 = 2x-90+x
⇒90 = 3x-90
⇒3x=180
⇒x=60
Now,
⇒y = 90 - x
⇒y=90-60
⇒y=30
Therefore, x=60 & y=30
In an competitive examination there were 60 questions.The correct answer would carry 2 marks and 1 mark would be subtracted.Yaahwant had attempted all the questions and he got total 90 marks.Then how many qst he went wrong??
Solve this sum in 'Linear equation in two variables form' pllzzzzzzz