Combined Slide result not what i was expecting!!

Hi

I am struggling with a combined result quiz not showing the "correct" results!

I have 6 quizzes, 5 of them have 3 questions and 1 has 5 questions

My combined results slide is not showing the correct score and failing the student even when they have met the criteria for passing the course  - ie they need to pass  5 of the quizzes to pass the course

Each quiz has a pass score of 80% (I have also set the combined quiz pass score to 80% not sure if this is correct)

I have seen another discussion saying that the combined result is based on the quiz scores and is also weighted if all quizzes don't have the same number of questions (ARGH!)..

So - If I set the scores for the 5 x 3 question quizzes to 10 points per question (30 total per quiz) and set the score to 6 points per question for the 5 question quiz (also 30 total per quiz) Should that then give me a accurate total score rather than a weighted one? 

Right now the combined quiz is showing a fail even if the learner passes 5 of the quizzes (I am also tracking the score on the combined result slide and it doesnt add up to the number of questions answered correctly 

Could that be because that some quizzes have passed with 100% questions answered correctly.. some answered just enough questions correctly to pass, and one where only one question was answered correctly (that's not enough to pass the quiz ..so is a fail!)

Do I need to make the pass score for each quiz 100% for the combined score to work correctly or change the pass score for the combined quiz?

If the latter, how do I work out what I should set the combined pass score/percentage to, to ensure it shows a pass regardless of which of the 6 courses were failed and regardless of whether the learner passed with 100% or 80 % of the questions answered correctly (hope this makes sense!!)

Some help with this would be appreciated, as it is driving me made and I need to complete this training (yesterday!!)