On a 26 question test, five points were deducted for each wrong answer and eight points were credited for each correct answer. If all the questions were answered, how many were correct if the score was zero?
(a)6
(b)9
(c)10
(d)13
Answer
Answer (as printed): C
Explanation
Let the number of correct answers be $x$. Then, number of wrong answers $=(26-x)$. $\therefore \quad 8 x-5(26-x)=0 \Rightarrow 13 x=130 \Rightarrow x=10$.
Explanation as extracted from the printed page; notation may be imperfect.