A coastal geologist estimates that a certain country’s beaches are eroding at a rate of 1.5 feet per year. According to the geologist’s estimate, how long will it take, in years, for the country’s beaches to erode by 21 feet?

Explanation

To solve the problem of how long it will take for the country's beaches to erode by 21 feet at a rate of 1.5 feet per year, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the erosion rate**: The problem states that the beaches are eroding at a rate of 1.5 feet per year.

2. **Determine the total erosion needed**: We need to find out how long it will take for the beaches to erode by 21 feet.

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