Answer:
You would need .75 cups of water (or 3/4 cups) if there is only 1.5 cups of pancake mix left
Explanation:
So the ratio of water to pancake mix is 2.75 : 3.5 (which makes 19 pancakes)
To get from 3.5 cups of pancake mix to 1.5 cups of pancake mix you would subtract 2 cups. Since this is a ratio, you would not only subtract 2 cups from the pancake mix, but also from the water. 2.75 - 2 = .75 Therefore, you would need .75 cups of water (or 3/4 cups) if there is only 1.5 cups of pancake mix left. Hope this helps!