The first question may be – Are you are married ? and Second question could be – When are you planning to get married ? If you answer both the questions as married and planning to get married in 30 days. This means you have answered without reading.
If identical answers are given for the same survey from the same IP address, it could mean that a single person has given the same answers for different people without they actually filling up the survey.
Our system has a process to check if the survey was filled too fast or by pasting from somewhere or random keys were pressed like “123” or “xyz” such surveys would get rejected.