Iwill upvote on every answer.

amy and her sister are making lemonade for the school dance. their recipe makes 2 quarts of lemonade. if they make 35 times the recipe, how many gallons of lemonade will amy and her sister have?

1 serving is 2 quarts
so 35 servings is 35 times the quantity of 1
the amount of 1 serving is 2 quarts
2 times 35=70 quarts

but wait, there's more
they want it in gallons

so
4 quarts=1 gallon
divide by 4
1 quart=1/4 gallons

we got 70 quarts
70 times 1/4=70/4=35/2=17.5 gallons

they have 17.5 gallons or 17 and 1/2 gallons