Ebony is building a shelf to hold the two boxes shown. what is the least width she should make the shelf?

There exists the same question from other source that shows the two boxes.

Box 1 has a length of 4/5 feet
Box 2 has a length of 3/4 feet

Because Ebony is trying to find the total amount of space needed to hold the boxes, use addition. 

Here, is the solution:
= 4 / 5 + 3 / 4
= (16 + 15) / 20
= 31 / 20

So, Ebony can make a shelf at least 31/20 feet wide or 1 11/20 feet.