Could I please have some help with these 2 questions?

1. In a maths competition with 15 questions, 6 marks are given for each correct answer, 0 marks for each wrong answer and 3 marks for no answer. Bill scored 51 points in the competition. What is the greatest number of wrong answers he could have had.

2. A bi-athlete travels 30km in 2.25 hrs. She cycles part of the way at 20 km/h and runs the rest at 8 km/h. How far did she run?