The South Padre island crew built an average of 208.5 feet per month, which means that in 2.5 years ( or 30 months ) this crew built
6255 feet of the bridge.
We are told that the two crews together built 12,513 feet of bridges. Meaning Port Isabel crew built
6258 feet of the bridge.
(a).
Port Isabel crew built
(b). Port Isabel crew built 6258 feet while South Padre crew built 6255 feet of the bridge.