Answer:
The bookshelf will fit between the windows with 1 inch remaining.
Step-by-step explanation:
Let w represents the width of the bookshelf,
According to the question,
The width of a bookshelf must be no greater than 6.5 feet for being fit between the windows.
⇒ w ≤ 6.5 feet,
⇒ w ≤ 78 inches ( 1 foot = 12 inches )
Given,
w = 77 inches
Since,

Thus, the book self will be fit between the window,
Also,

Hence, the bookshelf will fit between the windows with 1 inch remaining.