Help with managerial accounting??

Karney Company has revenues of $500,000, variable costs of $350,000, and fixed costs of $135,000. The sales price per unit is $100 and the Variable Cost per unit is $70, at this level of sales the Fixed Costs per unit is $27.

1) Karneys marketing manager believes that by increasing the advertising budget by $10,000, Karneys sales volume will increase by 5%. Should Karney spend the additional $10K on advertising? If they do, how will NOI change?

2) What is Karneys degree of operating leverage at revenues of $500,000? Given that degree of OL, by how much will Karneys NOI increase if sales increase by $10,000?