What is the maximum distance in feet form the first fastening of intermediate metal conduit that is permitted to be located a maximum distance of ___ feet from a junction box where structural members do not readially permit fastening of the conduit.

What is the maximum distance in feet form the first fastening of intermediate metal conduit that is permitted to be located a maximum distance of ___ feet from a junction box where structural members do not readially permit fastening of the conduit.