When the Glacier Zone Ice Rink opened, Betsy bought 18 ice-skating lessons during their grand-opening sale. She paid 387 in all. How much did each lesson cost?

Me. i can't figure out this question. give an explanation too. .

Extra points! find the missing dimension! need asap

Thanh and her crew are building a stage in the shape of a trapezoid for an upcoming festival. the lengths of the parallel sides of the trapezoid are 14 ft and 24 ft. the height of the trapezoid is 12 ft.what is the area of the stage? enter your answer in the box. ft²