Ronny, Celina, Jack, and Michelle together placed a total of 20 brownies on a tray. Ronny placed 0.15 of the brownies, Celina placed 3 of the 20 brownies, Jack placed 30% of the brownies, and Michelle placed the remaining brownies. Who placed the most brownies? (1 point)
Ronny placed: 0.15 x 20 = <<0.15*20=3>>3 brownies.
Jack placed: 30/100 x 20 = <<30/100*20=6>>6 brownies.
Michelle placed: 20 - 3 - 6 - 3 = <<20-3-6-3=8>>8 brownies.
Therefore, Michelle placed the most brownies, 8 > 6 > 3. Answer: \boxed{\text{Michelle}}.