sentence1: Chang Li has pet cockroaches that multiply at the same rate every week .
  The first week he had 5 , the next week he had 10 , the second week he had 20 , and the fourth week he had 80
sentence2: Chang Li has pet cockroaches that multiply at the same rate every week . The first week he had less than 7 , the next week he had 10 , the second week he had 20 , and the fourth week he had 80