Mr. Olin bought 6 sketchbooks for the students in his art class. Each sketchbook was on sale for $3 off. If the sketchbooks cost $18 total before tax, what was the original price of each sketchbook? HELP PLEASE.

Mr Olin bought 6 sketchbooks for the students in his art class Each sketchbook was on sale for 3 off If the sketchbooks cost 18 total before tax what was the or class=