A cоntinuоus beаm's flexurаl reinfоrcement must extend аt least _____ from the point where it is no longer needed to resist tension. Assume f'c = 4,000 psi, fyt = 40,000 psi, d = 24 in., w = 16.5 in., and t = 5 in. There are five No. 6 longitudinal tension bars and No. 5 stirrups at 12 in. o.c.