the equation to show how much lemon juice is needed for 10 ounces of water, would be 3 x 10. this would be the equation because we can see the water in ounces goes by 3, and the lemon juice in ounces goes by 1. the first ratio shown on the table, is 6:2, which can be simplified to 3:1. therefore if we needed 10 ounces of water, you would have to multiply 3 and 10.