Hi I need help with this question set 1-5 thank you!!

Oslo Company prepared the following contribution format income statement based on a sales volume of 1,000 units (the relevant range of production is 500 units to 1,500 units)

Sales $ 100,000

Variable expenses 65,000

Contribution margin 35,000

Fixed expenses 30,100

Net operating income $ 4,900

1. What is the contribution margin per unit?

2. What is the contribution margin ratio?

3. What is the variable expense ratio?

4. If sales increase to 1,001 units, what would be the increase in net operating income?

5. If sales decline to 900 units, what would be the net operating income?