First find the total time to paint the rose cups: 6 cups / 6 cups/hour = <<6/6=1>>1 hour
Then find the total time to paint the lily cups: 14 cups / 7 cups/hour = <<14/7=2>>2 hours
Then add the painting time for each type of cup to find the total painting time: 1 hour + 2 hours = <<1+2=3>>3 hours
Then divide Gina's total earnings by the number of hours she works to find her hourly wage: $90 / 3 hours = $<<90/3=30>>30/hour
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