Students take three multiple-choice tests, each with ten questions. A correct answer earns 5 marks. If no answer is given 1 mark is scored. An incorrect answer loses 2 marks. A student's final total mark is the sum of 20% of the mark in test 1, 30% of the mark in test 2 and 50% of the mark in test 3. One student's responses are summarized in the table below. Test 1 Test 2 Test 3 Correct answer 7 6 5 No answer 1 3 5 Incorrect answer 2 1 0 Write down three matrices such that matrix multiplication will give this student's final total mark and hence find this total mark.