Serena is building a bookcase she cuts two pieces of wood from one board one piece is 1 7/8 feey long and another is 3.5 ft long qhat is the total change in the lenght of the originl board

 feet

Step-by-step explanation:

The total change is the sum of the length of two boards she cut.

First board length is 1  7/8th feet. Let's change to improper fraction:

1 7/8 = 15/8 feet

Second board lengrh is 3.5 feet, or 3  1/2 feet. Let's change to improper fraction:

3  1/2 = 7/2 feet

Let's add the two:

The change in original board is 43/8 feet

9 x 8 divided by (5-3)=36