Final answer:
Anna ate less than 1 1/2 ounces of brown sugar.
Step-by-step explanation:
To determine if Anna ate more than 1 1/2 ounces of brown sugar, we need to find out how much brown sugar she used in the cake and how much she ate.
Anna bought 3/4 pound of brown sugar.
She used 2/5 of it to bake a cake.
2/5 of 3/4 pound = (2/5) x (3/4) pound = 6/20 pound = 3/10 pound.
Then she ate 1/4 of the cake.
1/4 of 3/10 pound = (1/4) x (3/10) pound = 3/40 pound.
Now we need to convert pounds to ounces since the given value is in ounces.
1 pound is equal to 16 ounces.
So, 3/40 pound is equal to (3/40) x 16 ounces = 3/5 ounce.
Therefore, Anna ate less than 1 1/2 ounces of brown sugar.