Answer:
16.65 feet
Step-by-step explanation:
Okay, we have three boards that are each 6.85 feet long. If we cut 3.4 feet off one board, that board has:
6.85
−
3.4
=
3.45
feet left
If we cut off 0.5 feet off another board, that board has:
6.85
−
0.5
=
6.35
feet left
So, if we take our three new boards, the total length of plywood left is:
6.85
+
3.45
+
6.35
=
16.65
feet
Hope this helps!