To find the width of the garden, let’s break it down step by step:

1. Number of plants: 21
2. Space between each plant: 50 cm
3. Space at each end of the garden: 50 cm (both ends)

Step 1: Total space between plants

There are 21 plants, meaning there are $21 - 1 = 20$ gaps between them. Each gap is 50 cm wide.

$20 \times 50 = 1000 \, \text{cm}$

Step 2: Add the space at the ends

There is 50 cm at each end of the garden, so:

$50 + 50 = 100 \, \text{cm}$

Step 3: Total width of the garden

Now, sum the total space between the plants and the spaces at the ends:

$1000 + 100 = 1100 \, \text{cm}$

Final Answer

The total width of the garden is:

$1100 \, \text{cm} \, = \, 11 \, \text{meters}.$

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Do you need more details or have any further questions?

Here are some related questions:

1. What if the plants were spaced 60 cm apart instead?
2. How would the total length change if there were 25 plants?
3. If the garden were rectangular, what would the area be if the width was 2 meters?
4. How many additional plants could fit if we reduced the spacing to 40 cm?
5. How would the answer change if only one side had a 50 cm buffer?

Tip: Remember to subtract 1 from the number of plants to determine the number of gaps between them!