Final answer:
In Bootstrap 3, the number of columns a div will span at an md viewport depends on the class applied. Without knowing the specific class, it's impossible to determine the width. Bootstrap columns have consistent spacing due to padding.
Step-by-step explanation:
The question refers to how a div will be displayed in a Bootstrap 3 grid system at a medium (md) viewport size. Bootstrap 3's grid system is based on 12 columns, so the number of columns wide a div can span depends on the class assigned to it. For example, if the class is col-md-6, the div would span 6 columns. If the class is col-md-12, it would span all 12 columns. Without the specific class, we cannot determine the width.
Beth's comment regarding the columns being closer at the edges suggests a misunderstanding. Bootstrap columns include padding on the left and right sides, creating gutters between columns. The spacing should be consistent across all columns if implemented correctly.