Since 9 questions is 60% of the exam, you must find 100%. You could find the value of 10% by dividing 60 by 6. You do the same to 9, divide by 6 to get 1.5. Now that you have the value of 10% you can multiply 10% by 10 to get 100. You also do the same to 1.5. Your answer should be 15, if not check your work again.
