Markup = 1,000,000 x 48% / 520,000
Note: Gross profit = 1,000,000 (projected annual sales) x 48% (profit margin) / 520,000 {1,000,000 - 480,000 (48% profit margin)}
Therefore,
Markup = 480,000 / 520,000
Markup = 92.3 percent
Now,
B 100,000 (that we calculated earlier - 10% of annual projected sales of 1M) x 92.3 percent = adjusted low budget
= B 92,308 (it means that you must spend at least 92,308 baht / year on your advertisement)
Repeat the same step by replacing 100,000 with 120,000 and 10 percent with 12 percent to get the adjusted high budget for the year.
= B 120,000 x 92.3 percent
= B 110,760 (it means the max you can spend is 110,760 baht / year on your advertisement)