A city planner has placed a square wading pool in the center of a park. The pool is surrpunded by a square fence, 20 meters wide. The tiles for the floor of the wading pool cover 121 sqaure meters. How wide is the wooden deck sprrounding the wading pool?

sqrt(121) = 11

so pool is 11 by 11
11 + 2w = 20
2w = 9
w = 4.5

To find the width of the wooden deck surrounding the wading pool, we need to subtract the area of the wading pool itself from the total area of the pool and the deck. Let's break down the problem step by step:

1. Calculate the total area of the pool and the deck:
- We know that the square fence surrounding the pool is 20 meters wide, so the total side length of the square pool and deck is (20 + 20) = 40 meters.
- Therefore, the total area of the pool and deck is 40 meters * 40 meters = 1600 square meters.

2. Subtract the area of the wading pool from the total area of the pool and deck:
- Given that the area of the pool is 121 square meters, we subtract this from the total area we calculated in the previous step: 1600 square meters - 121 square meters = 1479 square meters.

3. Determine the width of the wooden deck:
- The wooden deck surrounds the wading pool on all four sides, so the width of the deck is the same on all sides.
- Since the pool and deck together form a square shape, the width of the deck will be equal to the side length of the pool and deck minus the side length of just the pool.
- The side length of the pool and deck is the square root of the total area (1479 square meters), which is approximately 38.478 meters.
- The side length of the pool is the square root of the area of the pool (121 square meters), which is 11 meters.
- Therefore, the width of the wooden deck surrounding the wading pool is approximately 38.478 meters - 11 meters = 27.478 meters.

So, the width of the wooden deck surrounding the wading pool is approximately 27.478 meters.