Sales quantity variance

Hi there,
I had my PM exam today and I’m confused. In a Section B question was asking for the sales contribution quantity variance, is this the same as sales quantity variance. I had to change my answer calculating the variance of the contribution only ( deducting variable costs) which were given in the question, not sure, if this correct or it was just to confuse. Another question was to calculate the sales mix variance (“without including the word ” contribution”. And therefore I calculated the variance using the selling price.
Many thanks in advance.