Can you break down the solution for me for this math problem: Louise is an artist and needs to apply a coat of varnish to her latest paintings. Usually it takes 7 minutes for the coat of varnish to dry on one painting. However, today she is using a new varnish and it takes 12 minutes for the coat to dry. How much longer will it take for the coat of varnish on 6 paintings with the new varnish to dry as it would with the old varnish?