for 12 people it would be 2 liters of soda, 1 pint of sherbet, &3 cups of ice. you wanna make half as much as his recipe says so just divide everything by 2. then you can multiply what the half recipe calls for to serve 36 people by three. so it would be 6 liters of soda, 3 pints of sherbet and 9 cups of ice. I hope that made sense to you, it was kind of hard to out the explanation into words
