So this is not the answer that you want to hear, but Google does not publish what they consider a passing score. I do know that multiple answer questions are scored either all right or all wrong.
The passing score for each exam is confidential. It is determined by a panel of internal and external subject matter experts, following an industry-accepted standard setting process. The passing score is applied equally to all examinees. It is re-evaluated when changes are made to the exam content.
Are all questions on the exam scored?
No. At any given time, a small number of questions on our exams may be unscored. These are newly developed questions that are being evaluated for their effectiveness. This is a standard practice in the testing industry.