2 sliders counting the opposite way
I am having a little trouble figuring out an easy way to have 2 sliders, one counting from 10 to 30 and the other counting from 70 to 90. What I want is when one slider is dragged from 10 to 30 the result of the other slider would be that it goes from 90 to 70. I want this in steps of 1. They only way I can think of is to make 30 triggers to tell the second slider to be for example 73 when the first slider is 27. This seems time consuming. Is there an easier way?