Give the step-by-step reasoning process and then the final answer. Katya sold 8 glasses of lemonade and Ricky sold 9 glasses of lemonade. If Tina sold twice as many as Katya and Ricky's combined sales, how many more glasses of lemonade than Katya did Tina sell?
Katya and Ricky sold 8 + 9 = 17 glasses of lemonade. Tina sold 17 x 2 = 34 glasses of lemonade. Tina sold 34 - 8 = 26 more glasses of lemonade than Katya.
The final answer: 26.