Write a system of equations to describe the situation below, solve using substitution, and fill in the blanks.
Students in Mrs. Woodard's third grade class are working on times tables, and they
demonstrate mastery by passing tests. Josie has passed 10 tests so far. Her classmate,
Denise, has passed 2 tests of them. From now on, Josie plans to take and pass 2 tests per
week. Meanwhile, Denise plans to do 3 per week. At some point, Josie will catch up to
Denise. How long will it take? How many tests will each child have passed?