Paquito el Tech Ltd is a company that manufactures and sells high-end tech gadgets. They sell each gadget for $200. The variable cost of producing and selling each gadget (including direct materials, direct labor, and variable overheads) is $120. The fixed costs, such as rent and salaries, amount to $400,000 per month.

1. Calculate the contribution margin ratio for GearTech Ltd.

2. How many gadgets does GearTech Ltd need to sell each month to break even?

3. If GearTech Ltd wants to achieve a monthly profit of $100,000, how much in sales (both in terms of units and dollars) do they need to achieve?

4. If the company decides to increase its advertising budget by $20,000 per month, by how much would sales need to increase for the additional advertising to be justified?