Sales Variances Q225 Kaplan Kit

Fort Co produces and sells 3 models of cars The drastic, The Bomber, the Cracker.
Allof the cars are priced to achieve 10% mark up on standard cost.Fot the month of june
Fort Co budgeted to sell 30,000 units of drastic and so have 10% market share of the budgeted sales at a price of $10,600 each.Fort Co actually achieved 15% share of the market, though the market had actually contracted by 5%.

the following information is available for july.

Drastic Bomber Cracker
Sales units:
Budgeted 27,000 15,000 18,000
Actual 26,000 16,000 14,000
Budgeted sales Price $10,600 $13,250 $16,960

Calculate marker share and size variance for drastic

I figure out the whole answer except this bit where actual market size is calculated in answer it says 30,000/0.1 x0.95=285,000
i dont know how to figure out this in wasy way, i know this relates to 10% market share and 5% market actually contracted, could you please help me to understand this calculation.

many thanks