Need help with both requirements

Required Information [The following information applies to the questions displayed below! Data for Hermann Corporation are shown below: Selling price Variable expenses Contribution margin Percent Per Unit of Sales $90 100% 63 70 $22 JON Fixed expenses are $30,000 per month and the company is selling 2,000 units per month Required: 1-a How much will net operating income increase (decrease) per month if the monthly advertising budget increases by $5,000, the monthly sales volume increases by 100 units, and the total monthly sales increase by $9,000? 1- Should the advertising budget be increased