To find out how many trays of muffins Mrs. Rose made, you need to determine how much flour she used for the cakes and then subtract that from the total flour she started with (18 pounds).
Let's calculate:
First, you need to figure out how much flour was used for the cakes. If we let "x" represent the amount of flour used for the cakes, and we know that Mrs. Rose kept aside 1/4 of the flour for the cakes, we can set up the equation:
(1/4) * 18 pounds = x
Now, calculate:
(1/4) * 18 = 4.5 pounds
So, Mrs. Rose used 4.5 pounds of flour for the cakes.
Now, to find out how much flour was used for the muffins, subtract the flour used for the cakes from the total amount of flour:
18 pounds (total) - 4.5 pounds (cakes) = 13.5 pounds of flour for muffins.
Given that she used 1/6 of a pound of flour to make one tray of muffins, you can find the number of trays of muffins by dividing the remaining flour (13.5 pounds) by the flour per tray:
13.5 pounds / (1/6) pound per tray = 13.5 / (1/6) = 13.5 * (6/1) = 81 trays
So, Mrs. Rose made 81 trays of muffins.