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?

To answer the question above, evaluate the number of cookies each of them placed on a tray. The calculations are shown below,

Ronny              C1 = 0.15 x 20 = 3

Celina              C2 = 3

Jack                 C3 = 0.30 x 20 = 6

Michelle           C4 = 20 - (3 + 3 + 6) = 8

From the calculation above, Michelle placed the most number of brownies on the tray.