Gutierrez Company has four operating divisions. During the first quarter of 2014, the company reported aggregate income from operations of $199,700 and the following divisional results.

Division
I II III IV
Sales $248,400 $196,300 $499,900 $446,900
Cost of goods sold 202,500 190,300 302,200 246,900
Selling and administrative expenses 74,300 64,900 60,000 50,700
Income (loss) from operations $ (28,400) $ (58,900) $137,700 $149,300

Analysis reveals the following percentages of variable costs in each division.

I II III IV
Cost of goods sold 77% 90% 78% 77%
Selling and administrative expenses 38% 70% 49% 59%

Discontinuance of any division would save 50% of the fixed costs and expenses for that division.

Top management is very concerned about the unprofitable divisions (I and II). Consensus is that one or both of the divisions should be discontinued.

Compute the contribution margin for Divisions I and II:

Please explain how you got it thanks.