Nikko runs 6 miles a day and 3 days a week. How many weeks will it take Nikko to run 198 miles?
Nikko runs a total of 6 x 3 = <<6*3=18>>18 miles a week.
Therefore, it will take him 198/18 = <<198/18=11>>11 weeks to run 198 miles. Answer: \boxed{11}.
Therefore, it will take him 198/18 = <<198/18=11>>11 weeks to run 198 miles. Answer: \boxed{11}.