A survey of shoppers at a grocery store found that 40%

To find out how many shoppers were buying food for a week or more, you can multiply the total number of shoppers surveyed by the percentage of those buying food for a week or more.

Given:

- Total shoppers surveyed = 50
- Percentage buying food for a week or more = 40% = 0.40 (as a decimal)

Now, calculate the number of shoppers:

\[
\text{Number of shoppers} = 50 \times 0.40 = 20
\]

So, 20 shoppers were buying food for a week or more.