Andrea get 12 correct answers

The number of questions on the test could be 20, 25, 50 or 100. Each would give the same answer.

Andrea has 12 correct answers.

Answer is 12......For suppose no. of questions are 20 carrying 5 marks each. They got 3/4th of their answers correct i.e. 60 answers out of 80. Apart from Andrea others got 12 wrong answers in total. So Andrea's got 8 wrong answers out of 20. So,Andrea has 12 correct answers....:-) The answer will be same for any no. Of questions........