SOLUTION: David entered a quiz. For each correct answer three points were added; for each incorrect answer one point was deducted.The quiz had 100 questions and David scored 176 points. How

Question 875702: David entered a quiz. For each correct answer three points were added; for each incorrect answer one point was deducted.The quiz had 100 questions and David scored 176 points. How many questions did he answer correctly?
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
correct answers be x
and wrong answers be y
x+y=100
3x-y=176
x= number of correct answers
y= number of wrong answers

1 x + 1 y = 100 .............1

3 x -1 y = 176 .............2
Eliminate y
multiply (1)by 1
Multiply (2) by 1
1 x 1 y = 100
3 x -1 y = 176
Add the two equations
4 x = 276
/ 4
x = 69
plug value of x in (1)
1 x + 1 y = 100
69 + y = 100
y = 100 -69
y = 31
y = 31
x= 69 number of correct answers
y= 31 number of wrong answers
m.ananth@hotmail.ca

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