Q: 28 (IAS/2010)

A paper had ten questions. Each could only be answered as True (T) or False (F). Each candidate answered all the questions. Yet, no two candidates wrote the answers in an identical sequence. How many different sequences of answers are possible?
question_subject: 
Maths
question_year: 
2010
question_exam: 
IAS
question_sub_subject: 
Mathematics
question_topic: 
Mathematics
stats: 
0,216,208,72,56,80,216