For every cup of seltzer you use, how much orange juice do you use?

To determine the ratio of seltzer to orange juice, you will need to provide the desired ratio. For example, if you want to make one serving with a 1:1 ratio of seltzer to orange juice, you would use equal amounts of each. If you prefer a different ratio, such as 2:1 (two parts seltzer to one part orange juice), you would use twice as much seltzer as orange juice.

To calculate the amount of orange juice needed for a specific ratio, follow these steps:

1. Decide on the desired ratio of seltzer to orange juice.
2. Determine the amount of seltzer you plan to use (e.g., one cup).
3. Divide the amount of seltzer by the sum of the two parts of the ratio to obtain the amount of one part.
4. Multiply the amount of the one part by the number of parts of orange juice desired.

Example:
Let's say you want a 2:1 ratio of seltzer to orange juice, and you plan to use one cup of seltzer.

1. The ratio is 2:1 (2 parts seltzer to 1 part orange juice).
2. You have one cup of seltzer.
3. Divide 1 by the sum of the two parts of the ratio (2 + 1 = 3). 1/3 cup is equal to one part in the ratio.
4. Multiply 1/3 cup (one part) by 1 (the number of parts of orange juice desired). Therefore, you would use 1/3 cup of orange juice.

So, in this example, for every cup of seltzer, you would use 1/3 cup of orange juice to achieve a 2:1 ratio.