Final answer:
Darius has 8.15 pounds of potting soil left after using 11.85 pounds from the original 20 pounds.
Step-by-step explanation:
Darius started with 20 pounds of potting soil. After using 11.85 pounds for one flower bed, he wants to know how much soil he has left for the rest of the yard. To find the remaining soil, we subtract the amount used from the starting amount:
20 pounds - 11.85 pounds = 8.15 pounds
Therefore, Darius has 8.15 pounds of potting soil left to use in his yard.