Olongapo Sports Corporations distributes two premium golf balls - Flight Dynamic (A) and Sure Shot (B). Fixed expenses total $183,750 per month.

Monthly sales and the contribution margin ratios for the two products follow:

A B Total

Sales $150,000 $250,000 $400,000

CMratio 80% 36% ?

If sales increase by $100,000 a month, by how much would you expect the monthly net operating income to increase? What are your assumptions?