Okay, here we have this:
Considering that she gets paid 2,200 per month plus 6% of his sales and his brother earns $2,800 per month. The amount of total sales for which sales will make the salary higher than his brother's salary is the following:
2200+(Amount of total sales*6%)>2800
2200+(Amount of total sales*0.06)>2800
(Amount of total sales*0.06)>2800-2200
Amount of total sales*0.06>600
Amount of total sales>600/0.06
Amount of total sales>10000
Finally we obtain that the total sales amount that will make keshad's monthly salary greater than his brothers' monthly salary are sales greater than $ 10,000.