Answer:
70%
Explanation:
To find the percentage of shells with ridges, you can follow these steps:
Determine the total number of shells Margie collected, which is 50.
Calculate the number of shells with ridges, which is 35.
Divide the number of shells with ridges by the total number of shells and multiply by 100 to find the percentage.
(35 / 50) * 100 = 70
Therefore, 70% of Margie's shells had ridges.