SOLUTION: There are 20 questions in a short test. 5 marks are awarded for every correct answer, but 3 marks are deducted for every wrong answer or empty answer. I have 68 marks. How many que

Algebra ->  Linear-equations -> SOLUTION: There are 20 questions in a short test. 5 marks are awarded for every correct answer, but 3 marks are deducted for every wrong answer or empty answer. I have 68 marks. How many que      Log On


   



Question 681900: There are 20 questions in a short test. 5 marks are awarded for every correct answer, but 3 marks are deducted for every wrong answer or empty answer. I have 68 marks. How many questions have I answered correctly?
Answer by tsewaitung(11) About Me  (Show Source):
You can put this solution on YOUR website!
let I had answered x questions correctly and y questions wrong.
from the question, we have
x=20-y
5x=68+3y
by substituting the first equation into the second equation, we have
5(20-y)=68+3y
100-5y=68+3y
100-68=3y+5y
34=8y