Casen and Damon both reduced their weight by 18%. Before they lost the weight, Casen weighed 220 pounds and Damon weighed 186 pounds. What was the approximate amount of weight they lost combined?
Casen lost 220*18/100 = <<220*18/100=39.6>>39.6 pounds
And Damon lost 186*18/100 = <<186*18/100=33.48>>33.48 pounds
Thus, Casen and Damon lost 39.6 + 33.48 = <<39.6+33.48=73.08>>73.08 pounds. Answer: \boxed{73}.