Question

mr.wilson bought 4 tires for $390.60. If each tire cost $90 before tax was added. What tax rate did he pay on the tires?

Answer 1

First  calculate after tax tire price 
$390.60 / 4 = $97.65  after tax price per tire 
take the $97.65 divided by 90 
97.65 / 90 = 1.085 
1.085 is the rate of tax he paid per tire