Carbon-carbon bond-order in benzene is 1.5 due to
[tex] \sf \: Bond \: order= \frac{Total \: coordination \: bond \: resonating \: structure }{Total \: resonating \: structure}
[tex] \sf \: Bond \: order= \frac{Total \: coordination \: bond \: resonating \: structure }{Total \: resonating \: structure} [/tex]
[tex] \sf \: Bond \: order= \frac{3}{2} = 1.5[/tex]