Answer:
25.5 ft
Explanation:
Starting level: 33 ft
Each day the water recedes 0.5 ft.
Now we calculate the number of ft the water recedes in 15 days.
15 days * 0.5 ft/day = 7.5 ft
In 15 days, the water recedes 7.5 ft.
Level of water after 15 days:
33 ft - 7.5 ft = 25.5 ft
Answer: 25.5 ft