Answer: After 8 years, the coastline has receded 24 centimeters
Explanation:
We know that each year, the coastline recedes by 3 centimeters. If this occurs uninterrupted for 8 years, then the total distance that the coastline recedes is 8 times the amount that it recedes in a year, this is:
D = 8*3cm = 24cm
After 8 years, the coastline has receded 24 centimeters