Can you merge and randomise multiple question banks?

Hi Heroes,

Here's my dilemma. I'm making a quiz. Each question requires the user to pick from 3 different options. My stakeholders want to customise the ratio of questions with specific answers (e.g. 20% should be answer A, 30% answer B, and 50% answer C).  Also, they want a bank of questions available for each answer, so the game will be different each time.

So my idea was, create 3 banks of questions, 1 for each answer (A,B,C) with 10 questions in each. 

Bank A draws 2 questions from 10 that all have A as the answer.

Bank B draws 3 questions from 10 that all have B as the answer.

Bank C draws 5 questions from 10 that all have C as the answer.

Now I have 10 questions and the answers all fit my requested ratios, but I want to randomise them in the order they appear (e.g. the order might be A,C,B,C,B,C,A,B,C,C instead of A,A,B,B,B,C,C,C,C,C which is what it's like now).

Is this possible?

The only thing I can think of to get round it is make multiple question banks with the agreed ratio mix in each, and then use a random number variable to get them to a unique bank, but when my stakeholders say 'I want 30% of A instead of 20%' (which is an inevitability) it's more rework than I care to do!

Any assistance/remedy to this would be marvellous!

Many thanks,

Tom