Question: Jackson is clearing out his email inbox after noticing he has a whole lot of emails that he no longer needs and can delete. While he is cleaning his inbox, though, he keeps getting more emails. While he deletes 50 emails he gets another 15 sent to him. While he deletes 20 more he receives 5 more emails. After he is done deleting all his old emails he has just the new emails left, including 10 more that were sent to him. How many emails are there in Jackson's inbox now? Think carefully first, then make a decision:
Jackson deleted all his old emails so now he only has the new ones left, which he first gets 15 + 5 of = 20 emails. Then Jackson receives 10 more emails to add to the other 20 new ones, 10 + 20 = 30 new emails. So the answer is 30.