Excel / Access simple project series of IF Rules, and simple divisions to COUNT & SUM

Project Brief: I have a spreadsheet with approx. 1500 rows. In column A is potential revenue for each row. In the following x37 columns are categories. Each row belongs to a variety of categories, signalled by “YES”. I need someone to firstly sum the number of categories where YES appears for any year. Then you need to divide the sum in column A by the number of those categories that state YES on that row so that figure is divided equally by each category it contains. Then I need to sum each of the figures for each category. So for eg Row 1 If Column A is 100 and Plays, Dance, Music and Opera is YES. Plays + Dance + Music + Opera = 4 100/4 = 25 Play Total 25 Dance Total 25 Music Total 25 Opera Total 25 Row 2 If Column A is 200 and Musicals and Opera is Yes. Musicals + Opera = 2 200/2 = 100 Musicals Total 100 Opera Total 125 (because we are adding Row 1 to Row 2) Once that process is complete, I then want to understand the % of revenue, that each category represents. Thanks – ready to begin work now. Budget £35