I’d like to get help on this question – in terms of concept, the explanation makes sense. K-value and R-value can be understood to have an inverse relationship. However, the ARE also gives the equation “R = x / k” in their exam references. Under this equation, 8" concrete with K-value 10 does have a higher R-value (R-0.8) than 4" brick with K-value 8.4 (R-0.47). There seems to be a conflict between these concepts. Any help would be appreciated!