Creo que todavía son 20, ¿no?
The 20% increase will be 2 more glasses of lemonade. So therefore now being 12 glasses of lemonade will be multiplied by 9hrs with result of 108 glasses- this will be the total number of glasses sold
If one glass costs $0.50 then the total costs will be
108 glasses × $0.50
answering=$54.00