A8. In the test, there are 30 multiple-choice questions. A student gets 4 points for a correct answer and -1 point for an incorrect one. Miha answered all the questions and scored 60 points. How many questions did he answer correctly?
(A) 10
(B) 12
(C) 15
(D) 18
(E) 20
A8. Let the number of correct answers be denoted by $x$. Then the number of incorrect answers is $30-x$, and we can write the equation $x \cdot 4 + (30-x) \cdot (-1) = 60$. The solution is $x=18$.