Sale price variance

“Bloom is proud to announce that it has managed to maintain its market share despite an overall increase in the market size by 10%.” However, the sales director when challenged, by this journalist recently admitted having been forced to reduce prices by $1.50 per bunch on average on a budget volume of 12,000 bunches. All is not as rosy as it seems in Bloom’s garden!
If the standard variable cost of a bloom bunch of flowers is $20 and the standard contribution gained is $5 what is the favourable sales volume variance

Sir in this question I didn’t understand how they got 13200 as the actual units sold