Work done by 1st person = 100 forms per hourWork done by 2nd person = 90 forms per hourSo, total work in 1 hour would be = 190 forms per hourWork done in 5hours = 190* 5 = 950Now, remaining work is only 50 formsIn 1 hour or 60minutes, 190 forms are filled and 50 forms will be filled in = 60/190 * 50 = 15.7minutes or 16minutes (approximaty)Total time = 5hours 16minutes