Students in Mrs. Shepherd's third grade class are working on times tables, and they demonstrate mastery by passing tests. Kendall has passed 1 test so far. Her classmate, Rena, has passed 12 tests of them. From now on, Kendall plans to take and pass 4 tests per week. Meanwhile, Rena plans to do 3 per week. At some point, Rena will catch up to Kendall. How long will it take? How many tests will each child have passed?