On the second day, Maria sold 30 * 2 = <<30*2=60>>60 tulips.
She also sold 20 * 2 = <<20*2=40>>40 roses the second day.
On the third day, Maria sold only 10/100 * 60 = <<10/100*60=6>>6 tulips.
Over these three days Maria sold 30 + 60 + 6 = <<30+60+6=96>>96 tulips.
She also sold 20 + 40 + 16 = <<20+40+16=76>>76 roses.
So on the tulips Maria earned 96 * 2 = $<<96*2=192>>192.
And on roses Maria earned 76 * 3 = $<<76*3=228>>228.
In total, over these three days, Maria has earned 192 + 228 = $<<192+228=420>>420.
#### 420